Syria: how Bashar al-Assad's chemical arsenal became a strategic liability In Libya the pursuit and development of WMD over three decades was influenced by perceptions of external threat, and a perceived need to deter intervention by outside powers, notably the United States. Libya had been involved in supporting international terrorism from the early 1980s and feared US reprisal, a fear that was realised with the US air strikes of 1986. But as Gaddafi's international isolation deepened, and a series of UN Security Council Resolutions and sanctions were imposed in 1992-93 over the failure to hand over the Lockerbie terrorism suspects, Libya began to experience a rapidly deteriorating economic and social situation. A drop in oil prices and an inability to modernise the oil sector resulted in unemployment, declining living standards and resultant domestic political challenges to Gaddafi's authority. This altered domestic environment prompted the regime to initiate a series of steps from the mid-1990s, including an end to involvement in terrorism and handing over the Lockerbie suspects, in order to end the country's isolation and to bring in much needed overseas investment. The WMD decision was part of this political change of course. Crucially, both the Clinton and the Bush administrations told the Libyans that to re-engage with the US would require action on this front. The US-led intervention in Iraq on the grounds of forced disarmament in the first half of 2003 also seemed to accelerate and cement Gaddafi's decision. WMD had clearly come to be seen as a strategic weakness by the regime. Syria's decision to get rid of chemical weapons appears to echo this perception but in this case on the part of two key players: the Assad regime itself and its Russian patron. President Obama had made it clear in August 2012 that significant movement or use of chemical weapons constituted a "red line" for Washington. The tipping point of course came with the sarin attack on rebel held areas on the edge of Damascus on August 21. American pressure for military action to punish the indiscriminate use of chemical weapons grew rapidly despite the regime's denial of involvement. While Obama clearly does not want to get involved in another war in the region, the flagrant violation of his red line left him with little choice. His credibility was on the line and he had to honour his promise and prepare for military action. Any external use of force against Syrian forces and facilities, however localised or targeted, would certainly weaken the regime politically and militarily, and provide a major morale boost to opposition fighters, potentially tipping the civil war. The gravity of this situation was not lost on Assad. But perhaps more importantly, it was also not lost on Moscow. Russia has much to lose if Assad is toppled. Syria has long been an important strategic partner in the Middle East and its significance has grown since the end of the Cold War. The Syrian port of Tartus now provides Russia with its only naval base in the Mediterranean. Moreover, Russia sells a great deal of conventional weaponry to Syria and Russian firms have invested significantly in the Syrian energy sector. Moscow is also generally opposed to western intervention in the context of internal security situations. While it remains to be seen whether or not Syria will live up to its commitment to chemically disarm, and there are many reasons to doubt that it will, Russia's diplomatic manoeuvring has significantly reduced the likelihood of external intervention for the time being. Ultimately, however, for both Damascus and Moscow, it is the new and acute perception of liability that chemical weapons use has brought that is the real game-changer here. Wyn Bowen is Professor of Non-proliferation and International Security at King's College London, where he directs the Centre for Science and Security Studies. He is author of Libya and Nuclear Proliferation: Stepping back from the brink Matthew Moran is Lecturer in International Security at King's College London. He is author of Exploring Regional Responses to a Nuclear Iran: Nuclear Dominoes?