1. Assessing the potential for an Islamic State chemical attack in Europe
Since declaring its caliphate in June 2014, the Islamic State (IS) has become the focal-
point of British counter-terrorism efforts. Born out of the remnants of al-Qaeda in Iraq (AQI)
and catalysed by the on-going civil war in Syria, IS’ strategy has largely been regional in
focus. Distinct from other jihadists groups in that it effectively maintains territory that spans
large swathes of eastern Syria and western Iraq, its continued existence has been difficult
to define. At once an insurgency and a proto-state, its concentration has been on bringing
Muslims into the caliphate and expanding it (Zelin 2015), while largely leaving attacks on
Western targets to lone-wolf sympathisers. However, recent events, including IS’ alleged
downing of the Russian airliner in the Sinai (Withnall 2015) and the co-ordinated attacks in
Paris (Sterbenz, Price and Engel 2015) may suggest a shift to a more direct Western
strategy.
In the aftermath of the attacks, French Prime Minister Manuel Valls warned parliament that
there is a risk of a jihadist chemical weapons (CW) attack in France. (Telegraph 2015)
Although he did not cite any specific threat, it served as a stark warning. It is alleged that
IS possess CWs in Iraq and Syria, using them against civilians (Chivers 2015) and the
Kurdish peshmerga (Guardian 2015). Although terrorist attacks in Europe are a deep
cause for concern, CW attacks on urban populations are incredibly rare. This essay will
assess the likelihood of an IS linked CW attack in Europe, approaching it from three
distinct but interlinked angles: the history of jihadist attempts to weaponise chemicals, how
IS views the west as a target, and the difficulties associated with developing CW.
Historical attempts to develop chemical weapons by al-Qaeda and AQI
When assessing the interest that IS may have in CWs, it’s important to look at the history
of jihadist CW procurement. IS’ evolution is closely linked with al-Qaeda, particularly al-
Qaeda in Iraq, which can be said to be IS’ predecessor (Byman and Williams 2015).
The first reported attempts of al-Qaeda attempting to purchase CWs emerged in 1996
(Cole 2011, 60), while in 1998 a US airstrike took out a factory in Sudan, alleged to be an
al-Qaeda CW production facility (Cole 2011, 104). The aftermath of 9/11 saw a flurry of al-
Qaeda statements regarding its interest in CBRN weaponry, with reference often made
specifically to CWs. In June 2002, al-Qaeda spokesman Sulayman Abu Ghayth stated that

2. Muslims have the “right to kill” up to four million Americans “with chemical and biological
weapons, so as to afflict them with the fatal maladies that have afflicted the Muslims
because of the [Americans’] chemical and biological weapons.” (McNerney 2009, 456)
Although the extent and capabilities of al-Qaeda’s CWs programme was highly
exaggerated, it nonetheless created a fear factor and became an issue for western
governments. In 2002 a video emerged of al-Qaeda members using an unspecified gas on
dogs, which killed them. (Robertson 2002) Also in 2002 the Pentagon assessed that lab
equipment found in Kandahar, Afghanistan, was likely used by al-Qaeda for “a very limited
production of biological and chemical agents.” (Miller 2002)
Perhaps more significant, is the use of CWs by al-Qaeda-core affiliate, al-Qaeda in Iraq
(AQI). In 2004 the leader of Jama’at al-Tawhid wa al-Jihad, Abu Musab al-Zarqawi,
formally aligned with Osama bin Laden to form AQI. The bin Laden-Zarqawi relationship
was often fractious, with AQI’s violence on Shia muslims a source of contention. Although
al-Zarqawi was killed in a US airstrike in 2006, the group continued to exist and expand,
before eventually splitting with al-Qaeda in 2013 and becoming the Islamic State of Iraq
and al-Sham, now IS. Indeed, when current IS leader Abu Bakr al-Baghdadi declared the
caliphate in June 2014 he said that the group would continue along ‘the path that [Abu
Musab al-Zarqawi] trod … we God Willing, are following in his footsteps” (Lister 2015,
122). Indeed, much of the takfir ideology of IS is spawned from AQI and Zarqawism, in
particular its adherence to the teachings of the jihadist manual “The Management of
Savagery”. (Weiss and Hassan 2015, 40) (Crook 2014)
Before the recent allegations levelled at IS (Chivers 2015), AQI had been the only jihadist
organisation known to have used CWs. In April 2004, it became apparent that al-Zarqawi
was directly involved in the making of CWs, when US officials linked him to a ricin and
cyanide lab in Kirma, Iraq. (McInerney and Rhodes 2009, 425) Later that year, 3kg of
cyanide was found at the Baghdad house of Zarqawi aid Ahmad Fadhl Nazzal al-
Khalayila. (McInerney and Rhodes 2009, 440) In 2005, Zarqawi was ostensibly linked to a
planned chemical attack in Europe. (DW 2005) AQI’s most significant use of CWs though,
came in 2006 and 2007, when a series of car bombs containing chlorine gas were used on
Iraqi civilians and coalition forces. The chlorine was stolen rather than developed in a lab
(Binder and Moodie 2009, 143) The first attacks used roughly 100 pounds of chlorine,
which largely evaporated in the explosion. Later attacks used less explosive and up to one
tonne of chlorine, ensuring the chlorine had an effect on those AQI targeted. This suggests

3. a learning curve among the jihadists about the use of chlorine in attacks. (Binder and
Moodie 2009, 143) However, while the attacks caused deaths and mass casualties, it’s
unlikely that any deaths were as a result of chlorine exposure rather than the explosions
themselves.
While improvised chlorine bombs were arguably a successful attack, the bombs were
extremely crude and the chlorine was not utilised in such a way as to be properly effective.
Although the risk of an IS chemical attack exists, it’s important to note that a jihadist
organisation has never had a great deal of success attempting to develop such weapons.
The near and far enemy
Having looked at the history of CW procurement attempts by both core al-Qaeda and AQI,
it is important to understand their differing strategies, and how closely AQI’s strategy
influences IS today. In the early to mid 2000s, when core al-Qaeda was at its strongest, it
had a largely international focus on the “far enemy” that is the West. (Byman 2015)
Conversely, AQI’s remit was comparatively local. It rarely, if ever, sought to carry out
attacks in the West, preferring instead to tackle the “near enemy”, (Byman 2015) which
included coalition forces and the Shia-dominated government of Iraq, with attacks against
the West being of secondary concern. (Byman 2015)
IS largely follows the “near enemy” strategy of its predecessor, (Byman 2015) albeit with
caveats. So-called “apostate regimes” are what it considers its primary enemy, chiefly the
Assad regime and Iraqi government (Byman 2015). Its takfirism also sees it battle with
many other groups, including Hezbollah, Ahrar al-Sham, moderate rebels, and Jabhat al-
Nusra.
Sympathisers, foreign fighters, and the threat at home
Indeed, its strategy so far has been largely an insurgency and state-building project,
seeking to draw Muslims into its caliphate, rather than send them to Europe to wreak
havoc. (Zelin 2015) However, IS still employs strong rhetoric against the West.
Mohammad Emwazi, recently killed in a US drone strike, embodied this rhetoric, as many
of his videos threatened attacks against the West. (Jerusalem Post 2015) Research has
suggested that although IS focuses on a “near enemy” strategy, it prefers to inspire

4. sympathisers in the West to carry out “individual jihad” there, rather than using a
centralised approach. Two months before the Paris attacks, Thomas Hegghammer and
Petter Nesser, of the Norwegian Defence Research Establishment, authored a paper
(2015) assessing how IS views attacking the west. They found that there have been two IS
sympathiser attacks per month in the west since September 2014. Over the period
January 2011 to June 2015, they found evidence of 30 IS connected plots, 11 of which
(37%) were executed. Non-IS connected plots however, had a lesser execution rate of
(21%), but had a higher death rather at 2.9 deaths, compared to 1.4 deaths for IS
connected plots.
Furthermore, the authors found that 16 of the total 69 plots that they examined contained
at least one returned foreign fighter, and all but one of those plots occurred in Europe. Of
those 16 plots, 9 contained foreign fighters who had been to Syria. The authors conclude
that the rate of returning foreign fighter who plots an attack to be quite insignificant, at 1 in
360 who goes to Syria.
Much can be gleaned from these numbers, particularly when assessing the potential for a
CW attack in Europe. First of all, and worryingly, most of the plots examined occurred in
Europe (54%). Indeed, most of the plots the came to execution were in Europe (12), and
most of the plotters were also in Europe (80 out of 120 examined). Interestingly, plots
connected to IS tended to be less deadly but more successful. The authors note that these
types of plots tended to be small and low tech, involving stabbings and handguns, which
would suggest that IS connected plotters would be less likely to successfully use CBRN
weaponry, given the crudeness of IS-related attacks and the relative complexity of
developing and delivering CWs (discussed below). The authors also come to the
conclusion that IS sympathisers were a larger threat than returning foreign fighters, who
accounted for a relatively small threat: 1 out of every 360 who goes to Syria, though this
point may need to be reconsidered after the recent attacks in Paris.
The authors make clear that they hesitate to make predictions on future attacks from their
data. Nonetheless, while the vast majority of IS plots and executed attacks occur in
Europe, they’re relatively small in scale and lethality, which suggests the level of planning,
effort, and financial expense required for a chemical attack has so for not been mirrored in
any conventional weapons plots planned or carried out. For example, the vast majority of
attacks are lone wolf attacks, such as the Copenhagen attacks (Chrisafis 2015) and the

5. decapitation attack in Lyon (BBC 2015). Given the inherent difficulties of developing and
deploying CWs, and given jihadist history of being unable to do so, the trends of small,
low-tech IS-related attacks we have seen so far may suggest that a chemical attack is
unlikely.
Nonetheless, the threat of a CW attack still exists, and as such we must examine how a
chemical attack in Europe might come about.
Difficulties associated with producing a chemical weapon
Although we can argue that the threat of a chemical attack in Europe is small, given the
trend of unsophisticated methods of attacks so far (Hegghammer and Nesser), along with
jihadists’ poor track record for developing CWs, the threat still remains. Given this, it’s
worth discussing the different methods of obtaining a CW and which ones are most likely
to be used in the event of an attack.
It is quite likely that IS already possess CWs in Iraq and Syria, and likely acquired these
through theft. There are several incidents of alleged IS CWs use, but the most damning is
arguably the mustard attack on Marea in the Syrian province of Aleppo (Chivers 2015),
which wounded around thirty and likely caused the death of a baby girl. It is unclear how
IS would have come into possession of mustard agent, although in 2014 IS seized a
disused CW site at Muthanna, near Baghdad (BBC 2014), which manufactured sulphur
mustard (CIA 2007). Furthermore, despite a joint highly publicised OPCW-UN mission in
2013 to remove Syria’s declared CWs, there is evidence that the regime did not declare all
its sites and still possesses CWs such as sarin, and possibly mustard. (Entous and
Bendavid 2015) It is possible, that IS may have gained access to CWs from an undeclared
Assad regime CW site, though evidence thus far does not exist to suggest this.
Regardless, it seems unlikely that IS would be able to smuggle sufficient quantities of
chemical agent into Europe to carry out a large scale attack, although further investigation
on this possibility ought to take place.
Domestic production of CWs seems a more likely scenario for a jihadist attack in Europe,
particularly given that Hegghammer and Nesser’s findings saw that IS sympathisers
accounted for almost twice as many attacks as returning foreign fighters. In the past,

6. security services in Europe have foiled several jihadist plots to use CWs, including a 2001
plot to use sarin gas in London (Hastings and Bamber), and a 2002 plot to use cyanide to
attack the US embassy in Rome (BBC). In 2006, a second nerve gas plot in London was
broken up. (Alderson, Rayment and Hennessy). However, CWs have never been
successfully weaponised for an attack in Europe and no IS plots have been revealed
publicly.
According to Binder and Moodie (2009, 137), “[i]n heavily industrialised societies such as
Europe, obtaining the necessary equipment for small-scale batch production of CW agents
should not be an insurmountable obstacle”. However, while the production of CWs may be
possible, it will likely be to a small-scale and the real task is in improving the yield of the
product and scaling up the process to produce larger quantities, which would be required
for a mass-attack (Cole 2011, 42). Aum Shinrikyo are a good example of the difficulties
surrounding production of sufficient quantities and purities of chemical agent. Despite
several years of attempting to develop CW such as VX and sarin, their success rate was
poor. Although the sarin attack on the Tokyo subway killed 12 people, Aum Shinrikyo
suffered from severe delivery issues, which impacted the effectiveness of their CWs.
(Danzig et al 2011, 35).
While the Aum Shinrikyo case proves that manufacture and weaponisation of nerve
agents is inherently difficult, other agents may not be as difficult. Hydrogen cyanide, the
chemical widely assumed to have been used in the execution of dogs by al-Qaeda, can
possibly be weaponised using a crude device called the mubtakkar. It was the device to be
used for a chemical attack on the New York subway, before al-Qaeda deputy leader
Ayman al-Zawahiri abruptly called it off. (Salama and Bursac 2009, 110) However, Pita
(2007, 491) contends that hydrogen cyanide makes for a poor CW due to its “low
gas/vapor density, short persistence, and low thermal stability, all of which make it difficult
to weaponize in munitions”. Furthermore, Binder and Moodie (2009, 137) argue that the
production of blood agents such as hydrogen cyanide in suitable quantities is “unlikely”
due to substantial infrastructure required.
Vesicants, such as mustard sulphur, are also unlikely to be considered as suitable
weapons for a chemical attack in an urban area, due to the fact that they lack lethality,
their slow effectiveness and the large quantities of chemical required. (Binder and Moodie
2009, 137) In WWI for example, only 3% of mustard injuries were fatal. (Kaszeta 2014)

7. Indeed, given the track history among IS sympathisers for low-level attacks, it would seem
that the use of ready-made toxic industrial chemicals (TICs) such as chlorine, phosgene
and ammonia would be most likely chemicals used in an attack. IS’ predecessor, AQI
previously used chlorine attached to conventional explosives in Iraq in 2006 and 2007. For
a jihadist, the drawback of TICs compared to conventional CWs is that for lethality, a much
larger volume of TIC is required to cause significant casualties. However, due to the fact
that TICs have several other legal uses, they are prevalent in industrialised societies and
would most likely be the easiest chemicals to attain either through theft or purchase. A TIC
attack would likely be very crudely weaponised and only be used as a contaminant rather
than a lethal attack. (Cole 2011, 58) In the context of an IS-linked attack in Europe, where
the purpose of the attack would be to cause mass panic and fear, a contaminant attack
might serve a purpose.
Conclusion
It is clear from the empirical literature that jihadist groups such as al-Qaeda and its affiliate
AQI have never successfully weaponised a CW, despite various attempts to do so. The
use of chlorine in Iraq in 2006 and 2007 and them manner in which it was used suggests
that members of AQI had a poor knowledge of how best to utilise chlorine for attacks, and
also possibly its lack of lethality in such quantities.
In terms of the potential for a chemical attack in Europe, we can draw several conclusions.
Although the Paris attacks may represent a shift in strategy (it is too soon to tell), the vast
majority of IS-linked plots and attacks in Europe have been low-tech, low lethality attacks,
often by lone wolf sympathisers. Shootings and stabbings are a trend among these
groups, which require relatively little planning and expertise. It can be argued that this is
largely a feature of IS’ “near enemy” strategy, which contrary to al-Qaeda in the 2000s,
places the west as a secondary enemy. In terms of the potential for a chemical attack, the
risk appears quite low in this respect, given the inherent difficulties, and financial
constraints, associated with producing sufficient quantities of chemical agent and
weaponising them successfully. Aum Shinrikyo’s limitations serves as a good case study
in this respect.

8. In light of this, a sophisticated IS driven CW seems unlikely. However, if one were to take
place, the use of stolen or purchased TICs would be the most likely choice for would-be
terrorists. Using TICs as a CW is a relatively low-tech pursuit, although large quantities of
chemical would likely be required, and the numbers of deaths would likely be quite low.
Still, an attack such as this in Europe would generate much publicity and spark fear and
panic.
In conclusion, in seems unlikely that an IS associated mass chemical attack will be
launched in the near future.

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