Patricia Lewis
Research Director, International Security

Almost exactly a year ago, President Obama warned of 'enormous consequences' if the Syrian government crossed the 'red line' and used chemical weapons. Since then, rebel forces in Syria have made repeated claims of low-level chemical weapons use by the Assad regime. Journalists and non-governmental entities, along with sources contacted by intelligence services, have corroborated these accounts. 

The United Nations negotiated with the Syrian government to allow a team of inspectors access to operate under the UN Secretary General's Mechanism for Investigation of Alleged Use of Chemical and Biological Weapons. The mechanism, first established in 1987-8 as a response to the use of chemical weapons by Iraq, commits the Security Council to consider appropriate effective measures immediately with regards to any future use of chemical weapons.

The team of inspectors, drawn from the UN's roster of highly trained experts and laboratories, were admitted into Damascus last week with a mandate to investigate three instances of alleged chemical weapons use. However, their purpose and mandate changed when reports and video footage of mass killings in Damascus by what appeared to be a nerve agent hit the headlines the day after the inspectors arrived.

The team of UN experts are now taking samples from the events in Damascus of soil, dust, clothing, blood and other body fluids and tissues from survivors, and from the buildings and may - if permitted - be able to take them from people who have been killed. The samples are likely to contain traces of the deadly chemical itself and/or the compounds into which the chemical degrades. Collecting the samples will take time and then they will be sent to special laboratories for rigorous analysis before the results are told to the UN Secretary General and member states. 

There are concerns that because of the delay in getting to the site of the alleged attack, continued shelling of the area may have destroyed chemical and ballistic evidence. Shelling would have likely dispersed some of the deadly chemical and degradation products, thus increasing the degree of difficulty for identification. This shelling however will not have any impact on blood and tissue samples, or any other corroborating forensic evidence such as ballistic missile fragments. It is worth noting that the UN inspection team believed it worthwhile to carry out an investigation despite months passing since previous attacks. 

The UN team's mandate is to ascertain whether there was a chemical weapons attack; they are not mandated to discover who perpetrated the atrocity. However, the evidence they are likely to collect will assist in identifying the perpetrators. Each piece of evidence forms part of the puzzle. The first is the chemical used and its concentration. This helps narrow down who had access to it; if it is sarin for example (and the symptoms suggest it was) then the source of the weapon is likely to be government stocks. This is particularly true if the chemical weapon contains other chemicals such as stabilizers and dispersal agents. It could be from another organophosorus compound sourced from the agricultural sector, but it is unlikely that normal agri-products could have had such a devastating impact in such a short space of time. The inspectors need to do due diligence and investigate in order to rule out or still entertain the full range of possibilities.

Also important is where the shells containing the chemical arrived from. Are the shells from government/military stocks? Or are they more 'home-made' improvised shells? Could they have come from a source other than the Syrian government? What direction did the missiles come from? All this information can then be coupled with radar, satellite imagery and eyewitness accounts to pin-point from where they were fired, and hence who fired the shells. The UN inspectors are not mandated to establish this, but the evidence may form part of their full-spectrum collection techniques.

Once the UN inspector's results are in, the UN Security Council will have to consider the most appropriate action and take into account several important factors.

The first is the upholding of international law. Syria may not be party to the global Chemical Weapons Convention but it is a member of the long-established 1925 Geneva Protocol against the use of chemical weapons in conflict; all countries that are party to these treaties – including Russia and China – have an obligation to enforce their provisions and act in the case of their breach. 

Equally important is the prevention of further chemical attacks. If no effective – not necessarily military – action is taken, then there are likely to be more chemical attacks. The consequences of no action, military or non-military, would be to allow whoever committed the attack to go unpunished and give the signal that the supporters of the world-wide ban on chemical weapons do not care about the law and the meaning of the law. It also again means – twenty-five years after the Halabja atrocity – that the people who were gassed will not be protected and defended.

If a further attack is thought imminent or if agreement for some form of military action is agreed at the UN Security Council, then an international 'coalition of the willing' could be established and include non-western and western countries. NATO could take action as it includes Turkey, a country strongly dedicated to the prevention of chemical weapons and possibly under threat of attack, by design or by accident. Military action however could backfire and put the focus on the 'coalition of the willing' as aggressors rather than as defenders. 

It is a very difficult call. To carry out military action will undoubtedly cost lives. To not carry out military action will also cost lives. Whose lives are saved and whose are lost is the decision that has to be addressed unless there is a way to end the war and prevent more such attacks.