Philip Gordon - Middle East adviser to President Obama (2013-15)

US military action against President Assad's forces in Syria seems imminent. President Trump told the Russians - Assad's military backers - to 'get ready' by way of a tweet. A spiral of events which began with an alleged chemical weapons attack by the Syrian Army is heading towards a dangerous confrontation between Washington and Moscow.

HARDtalk's Stephen Sackur speaks to Philip Gordon, Barak Obama's senior adviser on the Middle East in 2013, when Assad's use of chemical weapons came close to prompting a US military response. Did hesitation then sow the seeds of today's crisis?