New Developments in the Islamic State’s External Operations: The 2017 Sydney Plane Plot
October 18, 2017
Abstract: In late July, Australia uncovered a suspected terror plot that was distinctive among Islamic State plots discovered within Western countries in three key ways. The first was that the Islamic State mailed the alleged plotters a package that amounted to a bomb-making kit, overcoming the dilemma of how to enable untrained individuals to construct explosive devices. The second was the targeting of an international airliner, which the Islamic State had previously only attempted within the Middle East region. The third was that it involved an attempt to use an improvised chemical dispersion device containing hydrogen sulfide, after the airliner attempt was aborted. Each of these methods highlight evolutions in the Islamic State’s approach to external operations.
On the afternoon of July 29, 2017, members of the New South Wales Joint Counter Terrorism Team arrested four men.a This was not unusual; counterterrorism raids have been common in Australia for over three years. Ever since former Islamic State spokesman Abu Muhammad al-Adnani’s September 2014 global call to arms, Australia had experienced a rapid succession of terror plots that were often unsophisticated efforts involving knives and firearms.1 However, this time, as new security measures at airports delayed passengers for hours and details began to emerge of hidden explosive devices and a plan to produce poisonous gas, it quickly became clear that the authorities were dealing with a suspected plot that was dramatically different than earlier ones.2
After two of the suspects were charged on August 4, Australian Federal Police Deputy Commissioner Michael Phelan and New South Wales Police Deputy Commissioner David Hudson held a joint press conference. They outlined a plan for terror that was more ambitious than any of Australia’s earlier Islamic State plots and that differed significantly from other Islamic State plots in Western countries. The police alleged that the suspects had hidden an explosive device in a meat grinder and tried to place it on an Etihad airplane flying from Sydney to Abu Dhabi.3 After that failed, the suspects allegedly tried to build a chemical gas device, intending to kill a large number of people in an enclosed place.
This article examines the alleged plot and the implications of its distinctive features: how it was organized, the targets, and the intended weapons. In doing so, it highlights potential changes in the Islamic State’s external operations approach and how the threat to the West has evolved.
The Alleged Plot
Of the four suspects arrested on July 29, police charged two over the alleged plot.b Two brothers, 49-year-old Khaled Khayat and 32-year-old Mahmoud Khayat, were each charged on August 3 with two counts of “acts done in preparation for, or planning, a terrorist act.”4 They appeared in Parramatta Court on August 5 and were denied bail.5 Police were told to prepare a brief of evidence by October 27, and the two accused terrorists are next due in court on November 14.6
The two accused men are entitled to the presumption of innocence, and it is currently unclear how they will plead. This means that this analysis is based on allegations that have not yet been tested in court. The following paragraphs outline what the suspects are alleged to have planned, based primarily on the August 4 press conference, complemented by other sources.c The subsequent sections examine the plot’s significance if the allegations are accurate.
According to the allegations, Khaled Khayat was contacted in Sydney some time during April 2017 by one of his brothers, Tarek Khayat, who was fighting in Syria for the Islamic State.7 Tarek connected Khaled to a senior Islamic State figure, who police described as the “controller.” Khaled remained in contact with the controller and conspired over several months to carry out a terrorist attack, along with his younger brother Mahmoud.8 No details have been publicly revealed about the controller’s identity, other than his nationality is not Australian.
The controller instructed Khaled and Mahmoud to build an explosive device to be hidden inside a meat grinder. They did not have to source the material themselves as an Islamic State operative in Turkey mailed the explosive substance and other components through international air cargo.9 This was sent in one package, which amounted to a partially constructed improvised explosive device (IED) that “was fairly well advanced but not enough to be a fully initiated device.”10 The exact type of explosive is unclear, though police described it as “high end” and “military grade.”11 They reportedly consider it to be pentaerythritol tetranitrate (PETN).12
At this point, Australian authorities were unaware of the plot and the bomb’s construction. Neither Khaled nor Mahmoud had been of significant interest to authorities, except that the Australian Security Intelligence Organisation (ASIO) had interviewed Khaled shortly after Tarek arrived in Syria.13 Consequently, the plotters managed to build a “fully functioning IED” without being disrupted.14
On July 15, Khaled Khayat took another of his brothers to Sydney International Airport. Khaled had brought the explosive device with him, intending to place it in the baggage of his unsuspecting brother who was boarding an Etihad flight to Abu Dhabi.d However, Khaled aborted the plan at the last minute, leaving with the bomb while the brother boarded the plane without his luggage.15
It is unclear why they abandoned the plan at the airport. One possibility the police are investigating is that the luggage concealing the IED exceeded the weight limit.16 Regardless of the reason, Khaled took the device home and disassembled it with Mahmoud.
Khaled and Mahmoud then received instructions from the controller for a new attack, this time with a poisonous gas rather than an explosive. They began to experiment toward building an “improvised chemical dispersion device” that would release “highly toxic hydrogen sulfide.”17 The controller gave some advice on targets, focusing on “crowded closed spaces, such as public transport.”18 The Khayats obtained precursor chemicals and some components, and also undertook some experiments, but were “a long way from having a functional device” when authorities intervened.19
On July 26, a foreign intelligence partner (reportedly the United States or the United Kingdom) alerted Australia about the plot, activating the country’s federal and state counterterrorism machinery.20 The New South Wales Joint Counter Terrorism Team quickly placed the suspects under surveillance and undertook an investigation leading to the plot’s disruption three days later.21
Provided the above allegations are accurate, the plot is distinctive among Islamic State plots within Western countries in three key ways: the manner in which the Islamic State provided logistical support, the targeting of an international airliner, and the subsequent intention to use a chemical device.e
Police guard the passenger security check area at Sydney Airport on July 30, 2017, in Sydney, Australia, after an alleged terror plot that involved blowing up an aircraft. (Brook Mitchell/Getty Images)
Khaled and Mahmoud Khayat allegedly acted under direct instructions from a senior Islamic State figure but without having themselves traveled to Syria or Iraq to join the group. This makes the alleged plot an example of what have been described as virtually planned or remote-controlled.22 This refers to when Islamic State figures—usually based in Syria’s Raqqa province—guide external plots by communicating through online platforms with supporters in other countries. These virtual planners have guided plots in Europe, North America, Australia, Southeast Asia, and elsewhere. They provide Islamic State supporters with advice on targets, by designating venues to attack or even giving the name and address of an individual to murder, and on tactics, by advising how to maintain operational security, build a bomb, or carry out a beheading. The Islamic State’s virtual planners also help to assuage plotters’ doubts, sometimes providing emotional support up until the moment of attack, and ensure publicity by instructing perpetrators to send a martyrdom video or written statement for the Islamic State to release after the attack.23
A small proportion of virtually planned plots have gone beyond advice and involved the remote orchestration of logistical support. Sometimes virtual planners assisted these plots by sending money. Bahrun Naim, an Indonesian Islamic State operative based in Syria, wired money to finance operations in Indonesia.24 U.S.-based plotter Mohamed Elshinawy received money from the Islamic State sent through fraudulent eBay transactions.25 Sometimes logistical support was organized by contacting other individuals in the same country to provide equipment. For an intended attack in Hyderabad, India, the Islamic State arranged for the plotter to find a bag of pistols tied to a tree.26 The Islamic State similarly arranged for Sid Ahmed Ghlam, who planned a shooting attack against a French church in 2015, to find a bag of automatic weapons left for him in a parked car.27
In this case, the Islamic State did not use a contact already within Australia to support the Khayats. They instead used the postal service to send the necessary explosive substance and other components. It previously may have appeared that the Islamic State would only provide direct logistical support for centrally planned plots like the Paris attacks.28 The alleged Sydney plot demonstrates that the Islamic State has an interest in providing direct support even for virtually planned plots.
This method allowed the controller to overcome a dilemma faced by both the Islamic State and al-Qa`ida: how to enable untrained operatives to construct explosives. Aspiring jihadis are not always able to access training camps to learn such skills, which is one reason why they have often used blades, firearms, or more recently vehicles. Recognizing the value of bombing attacks, jihadi organizations have attempted to overcome this dilemma in various ways. They have produced bomb-making videos and instruction manuals that have proliferated widely online, and online jihadi forums like Shumukh al-Islam have hosted e-learning courses such as “Special Explosives Course for Beginners.” But bomb-making remains difficult for untrained plotters.29
The Islamic State’s virtual planning approach can assist bomb-making efforts by allowing for personalized instruction. In a plot uncovered in Melbourne in May 2015, Raqqa-based British jihadi Junaid Hussain instructed a Melbourne-based teenager in building IEDs, helping him to almost finish constructing several pipe bombs before his arrest.30 However, the alleged Sydney plot represents a newer and bolder method, which Paul Cruickshank described as an “IKEA model of terrorism.”31 The Islamic State mailed the alleged terrorists a package that was in effect a bomb kit and provided sufficient instructions for the recipients to finish construction.32 This represents a new development in the Islamic State’s virtual planning.
Another of the attack’s notable features was the target. No earlier jihadi plot in Australia is known to have targeted aircraft. Islamic State plots in the West have rarely targeted aviation, with the main exception being the bombings at Brussels Airport in March 2016.33 The rarity of such attacks is likely due to the difficulties posed by airport security. Robert Liscouski and William McGann have argued that it is highly unlikely for bomb-laden luggage to go through modern security procedures and fail to be detected. Despite innovative attempts by terrorists to design better bombs, the sophisticated explosives-detection tools used at airports in most developed countries, along with the layered security approach of integrating multiple methods (X-rays, sniffer-dogs, and sensors that detect explosive traces at a molecular level), make an undetectable explosive unlikely.34
Liscouski and McGann highlighted several vulnerabilities that terrorists targeting aviation would likely seek to exploit. One was for a bomb to be smuggled through a developing country’s airport with less sophisticated detection technology. Another was for a device to be missed by less rigorously trained staff. The third scenario was for a bomb to be placed via insider assistance at an airport. The al-Shabaab terrorists who smuggled a laptop bomb onto Daallo Airlines Flight 159 leaving from Mogadishu airport in February 2, 2016, exploited several of these vulnerabilities. On February 1, an airport worker sneaked the device through a gate reserved for employees and handed it to the suicide bomber, but the bomber’s flight was cancelled. The next day, the laptop was brought through an X-ray scanner, which staff failed to detect due to a lack of skills and experience. The bomb exploded on board but did not bring down the plane.f Another case of insider assistance was the destruction of Metrojet Flight 9268 from Sharm el-Sheikh to St. Petersburg in October 2015, killing 224 people. The device was reportedly planted by an EgyptAir mechanic whose cousin joined the Islamic State.35
The alleged Sydney plot demonstrates an ambitious plan by the Islamic State to destroy an international airliner without exploiting any such vulnerabilities. The alleged plotters pursued a high-risk plan. Intending to smuggle the bomb through Sydney International Airport’s screening process, and without any apparent help from the inside, their prospects were likely never high. The Australian Federal Police believe that the device would not have escaped detection. During the investigation, they created a replica of the device and tested at multiple airports whether it could get past security. On every occasion, it was detected.36
It is possible that the controller (the Islamic State virtual planner behind the alleged plot) underestimated the difficulty of getting past Sydney International Airport’s security measures. However, it is equally plausible that this was known to be a high-risk plan, but was judged as worth pursuing because aviation represented such a valuable target. Airlines have strong symbolic value, as they represent a country’s modernity and prestige. They have economic value, as an attack on aircraft can disrupt air travel and cause enormous economic damage. They also have publicity-generating value, particularly as such an attack impacts multiple countries. These factors have long made airlines a favored target for terrorists.
In the last decade, al-Qa`ida’s affiliate in Yemen (AQAP) has made a concerted effort to target planes. In 2009, AQAP operative Umar Farouk Abdulmuttalab smuggled a PETN bomb in his underwear on to a flight from Amsterdam to Detroit, but failed to detonate the main charge. In 2010, AQAP managed to get PETN bombs on board cargo flights, hidden in printer cartridges. They attempted a similar attack to the underwear bomb attempt in 2012.37 As outlined above, in February 2016, an al-Shabaab terrorist smuggled a laptop bomb through Mogadishu airport and detonated it on Daallo Airlines Flight 159, blowing a hole in the plane but only killing himself as the flight had not reached cruising altitude. A month later, there was an attempt to smuggle another laptop through a different Somali airport, but it exploded at a checkpoint.38
There have been constant efforts to make aviation a harder target. Billions of dollars have been spent on measures such as air marshals, body-scanners, and explosive trace detection. These measures have had substantial success and saved many lives, but they have not stopped planes from being attractive targets and have possibly made them a more tempting prize. Terrorist groups can point to any successful attack as a supreme example of penetrating the enemy’s defenses, and groups like AQAP celebrate even foiled plane plots such as the printer cartridge plot.39
The Islamic State showed less interest in targeting aviation, until recently. Its Sinai affiliate claimed to have bombed Metrojet Flight 9268, flying from Egypt to Russia, making clear that the Islamic State viewed aviation as a valuable target.40 Around early 2017, Israeli intelligence reportedly discovered that the Islamic State was working on explosives intended to get past airport security by appearing to be laptop batteries.41
Therefore, the alleged Sydney plot provides another example of the Islamic State’s interest in targeting aviation, continuing down the path established by al-Qa`ida and a range of earlier terrorist groups. While it may have earlier appeared that the Islamic State had far less of an interest in targeting aviation than al-Qa`ida, recent developments such as its laptop bomb ambitions could suggest this is changing and that the Sydney arrests provide further evidence toward this.
Chemical Weapon Use
A final feature of the plot was the planned use of poisonous gas. The Islamic State and its predecessors have long had an interest in chemical weapons. Abu Mus’ab al-Zarqawi’s pre-9/11 training camp in Herat, Afghanistan, included the creation of crude chemical weapons in its curriculum.42 When the U.S.-led coalition invaded Iraq in 2003, the only place it found active production of chemical weapons was in the district of Khurmal, within the autonomous Kurdish zone of Northern Iraq, at a facility run by al-Zarqawi’s network.43 From 2006 to 2007, the Islamic State of Iraq loaded chlorine canisters and explosives into trucks, and used them on the streets of Ramadi.44 From 2014 onward, Islamic State reportedly used chlorine in roadside bombs and mortars.45 By 2015, these chemical weapons efforts had expanded to include mustard gas, which they are believed to have used in both Syria and Iraq.46
These developments raised international concern. Australia’s Foreign Minister Julie Bishop warned in June 2015 that:
“Apart from some crude and small-scale endeavors, the conventional wisdom has been that the terrorist intention to acquire and weaponize chemical agents has been largely aspirational. The use of chlorine by Daesh and its recruitment of highly technically trained professionals, including from the West, have revealed far more serious efforts in chemical weapons development.” 47
The potential for these methods to be used in the West has been noted by scholars such as Petter Nesser, Anne Stenersen, and Emilie Oftedal, who posited that “IS [the Islamic State] has developed certain tactics on the ground in Syria that may, or may not be transferred to Europe. The most worrying development is IS’s active interest in, and use of, improvised chemical weapons such as chlorine bombs and mustard gas.”48 However, noting the difficulty of smuggling a chemical weapon into Europe, Nesser, Stenersen, and Oftedal suggested it was more likely that “that IS bomb-makers devise a way to make improvised chemical bombs from available materials.”49 This appears to have occurred in this case, as hydrogen sulfide can be produced from consumer products.50
Hydrogen sulfide is a toxic gas that interferes with cells’ ability to use oxygen. It is colorless and at high concentrations can cause immediate death. It is most commonly known for being used in suicides.51 A wave of such suicides began in Japan in 2008, with over 500 people killing themselves with hydrogen sulfide that year.52 This technique then spread to the United States and elsewhere, but was far less common.53 The toxicity of the gas has meant these suicides often caused wider harm. In one case, an individual in Japan using hydrogen sulfide to take her life caused 90 other people in the same apartment complex to become sick.54 Emergency responders have sometimes been hospitalized after attending the scenes of these incidents, due to exposure to the vapors.55
Whether hydrogen sulfide could be used effectively as a weapon for mass carnage is unclear. It has rarely been used as a chemical weapon, though the British did use it briefly in World War I.56 It has almost never been used in a terrorist plot, with one possible exception being a thwarted 1997 Ku Klux Klan plot in Dallas, Texas. Four Klan members planned to bomb a chemical factory, which contained tanks of hydrogen sulfide, as a diversion to carry out robberies.”57 There has been little public evidence of jihadi interest in this gas, with the significant exception of a manual posted on an al-Qa`ida in Iraq website in 2005 that included instructions for producing hydrogen sulfide, though Sammy Salama and Edith Bursac note that the manual did not outline a credible method for dispersing it.58 There has been some jihadi experimentation with dispersal devices for chemical attacks away from the battlefield. In the mid-2000s, jihadi websites shared instructions on constructing a chemical dispersal device called al-Mubtakkar for another gas, hydrogen cyanide.59 In 2003, a Saudi Arabia-based al-Qa`ida affiliate reportedly planned to use the device in a terrorist attack against the New York City subway before Aymen al-Zawahiri called it off.60 So while there have been some blueprints circulating among jihadi groups for chemical dispersal devices, it is not clear that there have been any optimized for hydrogen sulfide. It is unclear what sort of dispersal device the Khayats were allegedly planning to build, and their prospects for success may not have been high. Police have not alleged that the suspects came close to actually creating the gas or the dispersal device. At the press conference, they emphasized that “to make hydrogen sulfide … it is very difficult and very dangerous to get to the final product” and that the suspects were “a long way from actually doing that.”61
Australia is not new to terror plots inspired or guided by Islamic State. The country had experienced around a dozen such plots since September 2014, as well as five violent attacks, the most recent being a siege in the Melbourne suburb of Brighton in June 2017.62 However, the alleged Sydney plot indicated a plan for terror more ambitious than jihadi activity experienced earlier by Australia.
The alleged plot had three distinctive features, making it stand out from other Islamic State plots in the West. The first was that it was a virtually planned plot with direct logistical support, as the Islamic State effectively mailed a bomb-making kit, which has not been seen in other virtually planned plots. The second was that it was to be an attack within the West targeting an international flight. The third was that it was to be an attack within the West using a chemical device. It should not be assumed that this plot represents a new model, as one incident does not demonstrate a trend. However, what makes this plot have broader significance is that none of these three key features came out of nowhere. Each of them built on earlier developments in Islamic State tactics.
The first feature, direct logistical support for a virtually planned attack, represents a gradual evolution. In multiple earlier cases, Islamic State virtual planners had remotely orchestrated logistical support by wiring money or arranging for in-country contacts to provide weapons. Supporting plotters by directly sending a package containing the explosive substance and other necessary components was a logical step. It was also a potential game-changer, as it overcame the dilemma of how to enable untrained aspiring terrorists to construct explosives. The second and third features were a sharper break, as earlier Islamic State plots within the West had not involved attempts to bomb an airliner or use a chemical device. However, there had been evidence of Islamic State plans to smuggle bombs through airports in the Middle East and evidence that it used chemical weapons in Syria and Iraq. Therefore, the allegations that the Khayats targeted a plane and attempted to build a chemical device suggest that Islamic State has ambitions to use within the West tactics it previously used in the region.
This means that the alleged Sydney plot is unlikely to be an anomaly, and it can be anticipated that some of these features may appear in future plots. The Islamic State’s loss of territory within Syria and Iraq is unlikely to change this because virtually planned plots do not have to be run by individuals based within Islamic State territory. Virtual encouragement or direction has been provided to plotters in the West by individuals in Somalia, Libya, and the United Kingdom.63 Importantly, the alleged plot also demonstrates limitations faced by the Islamic State. The likelihood of getting a bomb through airport security was not high, and the plans for hydrogen sulfide do not appear to have progressed far. Therefore, allegations made against these two accused terrorists point both to the Islamic State’s ambitions for attacks in the West and the practical difficulties involved in carrying such ambitions out. Given the implications for how Islamic State’s approach to external operations is evolving, the case will be worth following closely.g CTC
Andrew Zammit is a Ph.D. candidate at Monash University. He has worked on terrorism research projects at Monash University and Victoria University, and his research on jihadism in Australia has been widely published. He co-produces the Sub Rosa podcast on security and human rights issues in Australia and Southeast Asia. His website is andrewzammit.org. Follow @Andrew_Zammit
[a] The New South Wales Joint Counter Terrorism Team is a combined federal and state counterterrorism unit, which includes members of the Australian Security Intelligence Organisation, the Australian Federal Police, the New South Wales Police, and the New South Wales Crime Commission.
[b] Another of the suspects, 50-year-old Abdul Merhi, was released without charge on August 2. The remaining suspect, 39-year-old Khaled Merhi, was charged with possession of a prohibited weapon (a taser) and released on August 6. Rachel Olding and Rachel Browne, “Man arrested over ‘Sydney Terrorism Plane Bomb Plot’ Released Without Charge,” Sydney Morning Herald, August 2, 2017; Rachel Olding, “Khaled Merhi Pleads Not Guilty to Weapons Charge After Sydney ‘Bomb Plot’ Raid,” Sydney Morning Herald, August 24, 2017.
[c] Usually, little information is available on terror plots in Australia immediately after suspects are charged, aside from media reporting whose reliability can vary depending on the individual journalists and their sources. More information becomes available as the court process proceeds, which can take several years. However, in this case, significant information is available as the press conference provided unprecedented detail on the allegations. This unusual step was taken due to the seriousness of the alleged plans and to dampen the widespread media speculation following the arrests.
[d] The police emphasized that they believe that this brother had no knowledge of the plot. “AFP and NSWP Discuss the Two Sydney Men Charged over Alleged Terrorist Acts,” Australian Federal Police National Media press conference, August 4, 2017.
[e] There is also another version of these events. In late August, Lebanon’s Interior Minister Nohad Machnouk gave a press conference presenting an account of the alleged plot that was different from the Australian version in several ways. It was claimed that the brother whose luggage was to conceal the bomb was, in fact, aware of the plot; that the bomb would likely have gotten past security if not for the weight limit; that there was also an attempt to hide a bomb in a Barbie doll; and that the Lebanese government had been monitoring the suspects for at least a year. Australian authorities have refused to comment on these claims. For this article, the author decided to go with the August 4 Australian Federal Police/New South Wales Police press conference account of these events, as this is the version put forward by those closest to the investigation and the version that will be tested in court. Rachel Olding, “Lebanese Authorities Monitored Australian Bomb Plot Suspects: Minister,” Sydney Morning Herald, August 22, 2017; “Aust Coy on Lebanon’s Terror Plot Claims,” SBS News, August 22, 2017.
[f] Colonel Hassan Ali Nur Shute, the chief prosecutor of the military court that prosecuted the suspects, blamed the security breach on the lack of skills by airport security personnel and that the technique used was not known by them. “They fitted the explosives in the laptop with sophistication,” he said. “It was difficult for the staff to detect. They have not seen that kind of technique used before.” Harun Maruf, “Officials: Mogadishu Flights Safe from Laptop Attacks,” VoA, April 25, 2017. See also Robert Liscouski and William McGann, “The Evolving Challenges for Explosive Detection in the Aviation Sector and Beyond,” CTC Sentinel 9:5 (2016).
[g] The author would like to thank Katrina Zorzi of Monash University for her helpful advice on this article.
 Andrew Zammit, “Australian Jihadism in the Age of the Islamic State,” CTC Sentinel 10:3 (2017).
 “Sydney Terror Raids: Airport Delays Expected as Security Increased Over Alleged Plot,” ABC News, July 30, 2017.
 Paul Maley, “From Syria to Sydney: How the Scheme Unfolded,” Australian, August 5, 2017.
 “Two Sydney Men Charged over Planned Terrorist Acts,” Australian Federal Police National Media, August 3, 2017.
 Nicola Berkovic, “Two in Court over ‘Sophisticated Plot,’” Australian, August 5, 2017.
 “AFP and NSWP Discuss the Two Sydney Men Charged over Alleged Terrorist Acts,” Australian Federal Police National Media, August 4, 2017.
 “AFP and NSWP Discuss the Two Sydney Men Charged over Alleged Terrorist Acts.”
 “AFP and NSWP Discuss the Two Sydney Men Charged over Alleged Terrorist Acts.”
 Ibid.; “Terror at the Terminal,” Australian, August 5, 2017.
 “AFP and NSWP Discuss the Two Sydney Men Charged over Alleged Terrorist Acts.”
 Riley Stuart and Louise Hall, “Sydney Terror Plot: How Police Dismantled Alleged Islamic State Plan Hatched on Home Soil,” ABC, August 3, 2017.
 “AFP and NSWP Discuss the Two Sydney Men Charged over Alleged Terrorist Acts.”
 Daveed Gartenstein-Ross and Madeleine Blackman, “ISIL’s Virtual Planners: A Critical Terrorist Innovation,” War on the Rocks, January 4, 2017; Bridget Moreng, “‘ISIS’ Virtual Puppeteers: How They Recruit and Train ‘Lone Wolves,’” Foreign Affairs, September 21, 2016; Thomas Joscelyn, “Terror plots in Germany, France were ‘remote-controlled’ by Islamic State operatives,” Long War Journal, September 24, 2016.
 Andrew Zammit, “The Role of Virtual Planners in the 2015 Anzac Day Terror Plot,” Security Challenges 13: 1 (2017): pp. 42-47. See also Seamus Hughes and Alexander Meleagrou-Hitchens, “The Threat to the United States from the Islamic State’s Virtual Entrepreneurs” CTC Sentinel 10:3 (2017); Rukmini Callimachi, “Not ‘Lone Wolves’ After All: How ISIS Guides World’s Terror Plots From Afar,” New York Times, February 4, 2017; and Moreng.
 Christopher S. Stewart and Mark Maremont, “American Pleads Guilty to Accepting Islamic State Money to Fund Terrorism,” Wall Street Journal, August 15, 2017.
 Jean-Charles Brisard and Kévin Jackson, “The Islamic State’s External Operations and the French-Belgian Nexus,” CTC Sentinel 9:11 (2016).
 Anne Stenersen, “Bomb-making for Beginners’: Inside an Al-Qaeda E-Learning Course,” Perspectives on Terrorism 7:1 (2013).
 DPP (Cth) v M H K (a Pseudonym)  VSCA 157 (June 23, 2017).
 “Mueller Exploring Financials of Trump; Starr on Fishing Expedition; Grand Jury Subpoenas in Russia Probe; McMaster At War with Trump’s Base; Sydney Police Foil Terror Plan. Aired 2-2:30p ET,” CNN Newsroom, August 4, 2017.
 David Wroe, “How ‘bomb kit’ delivery changed thinking about Australian border security,” Sydney Morning Herald, September 25, 2017.
 Pieter Van Ostaeyen, “Belgian Radical Networks and the Road to the Brussels Attacks,” CTC Sentinel 9:6 (2016).
 Robert Liscouski and William McGann, “The Evolving Challenges for Explosive Detection in the Aviation Sector and Beyond,” CTC Sentinel 9:5 (2016).
 “Exclusive: EgyptAir mechanic suspected in Russian plane crash,” Reuters, January 29, 2016.
 “AFP and NSWP Discuss the Two Sydney Men Charged Over Alleged Terrorist Acts.”
 Greg Miller and Karen DeYoung, “Al-Qaeda Airline Bomb Plot Disrupted, U.S. Says,” Washington Post, May 7, 2012.
 Liscouski and McGann.
 Justin V. Hastings and Ryan J. Chan, “Target Hardening and Terrorist Signaling: The Case of Aviation Security,” Paper for the Contemporary Challenges of Politics Research Workshop, University of Sydney, October 31, 2011.
 Zack Gold, “Wilayat Sinai Risks Backlash after Metrojet Bombing,” CTC Sentinel 8:11 (2015).
 David E. Sanger and Eric Schmitt, “U.S. Cyberweapons, Used Against Iran and North Korea, Are a Disappointment Against ISIS,” New York Times, June 12, 2017.
 Chris Quillen, “The Islamic State’s Evolving Chemical Arsenal,” Studies in Conflict & Terrorism 39:11 (2016): p. 1,020.
 Ibid., p. 1,021.
 Ibid., p. 1,023; Bill Roggio, “Another Chlorine Truck Bomb Found Near Ramadi,” Long War Journal, March 27, 2007.
 Quillen, p. 1,025; C.J. Chivers, “ISIS Has Fired Chemical Mortar Shells, Evidence Indicates,” New York Times, July 17, 2015.
 Quillen, pp. 1,025-1,026.
 Speech by Australia Foreign Minister Julie Bishop to Australia Group Plenary, Perth, Australia, June 5, 2015, as cited in Stephen Hummel, “The Islamic State and WMD: Assessing the Future Threat,” CTC Sentinel 9:1 (2016): p. 18.
 Petter Nesser, Anne Stenersen, and Emilie Oftedal, “Jihadi Terrorism in Europe: The IS-Effect,” Perspectives on Terrorism 10:6 (2016): pp. 19-20.
 Ibid., p. 20.
 “Chemical Suicides: The Risk to Emergency Responders,” U.S. Department of Health & Human Services, May 2, 2017.
 Kevin Poulsen, “Dangerous Japanese ‘Detergent Suicide’ Technique Creeps Into U.S.,” Wired, March 3, 2009.
 Daiichi Morii, Yasusuke Miyagatani, Naohisa Nakamae, Masaki Murao, and Kiyomi Taniyama, “Japanese experience of hydrogen sulfide: the suicide craze in 2008,” Journal of Occupational Medicine and Toxicology 5:28 (2010).
 Eline A.Q. Mooyaart, Egbert L.G. Gelderman, Maarten W. Nijsten, Ronald de Vos, J. Manfred Hirner, Dylan W. de Lange, Henri D.G. Leuvenink, Walter M. van den Bergh, “Outcome after hydrogen sulphide intoxication,” Resuscitation 103 (2016).
 “U.S. Holds 4 in a Bombing and Robbery Plot,” New York Times, April 24, 1997.
 Sammy Salama and Edith Bursac, “Jihadist Capabilities and the Diffusion of Knowledge” in Gary Ackerman and Jeremy Tamsett eds., Jihadists and Weapons of Mass Destruction (Boca Raton, Florida: CRC Press, 2009), pp. 110, 114.
 Ibid., p. 110.
 Ibid., p. 110.
 “AFP and NSWP Discuss the Two Sydney Men Charged Over Alleged Terrorist Acts.”
 Zammit, “Australian Jihadism in the Age of the Islamic State;” Andrew Zammit, “Understanding Australia’s Brighton Siege Terror Attack,” Jamestown Terrorism Monitor 15:14 (2017).
 Zammit, “The Role of Virtual Planners in the 2015 Anzac Day Terror Plot;” Hughes and Meleagrou-Hitchens; Georg Heil, “The Berlin Attack and the ‘Abu Walaa’ Islamic State Recruitment Network,” CTC Sentinel 10:2 (2017); Florian Flade, “Was das LKA bei Amris Terror-Chat mitlas,” Die Welt, March 27, 2017.