It is September 2012 and I am at the National Security Council in Downing Street. David Cameron is chairing a discussion about military options in Syria. Almost 40,000 civilians have been killed and thousands are displaced. The Chief of the Defence Staff explains how to establish a no-fly zone on Syrian territory and create a safe haven for refugees. Next up the heads of the intelligence services assess the opposition groups, some of whom are Islamist extremists. After a lengthy exchange of views the ministers agree not to take military action.

Fast-forward to August 2013, President Assad has used chemical weapons against his own people. Western powers are threatening military action. In a bizarre twist, I am in Afghanistan before the crucial vote in Parliament, with my inbox full of draft speeches about Syrian intervention: a tough juxtaposition as I visit the last forward operating base held by British troops in Helmand, the tail end of a 12-year intervention. Back in London there is high drama, the Government loses the vote on Syria and President Barrack Obama rows back from his commitment to bomb Assad.

The Middle East is never straightforward. The Syrian civil war involves ten separate conflicts involving scores of rebel groups fighting for control. Back in 2012 we were paralysed by this complexity and the likelihood, which came true in the form of Isil, that a rebel group would become more dangerous than the regime.

Read the full article in The Telegraph.