An in-depth examination of the United States' indirect intervention into the Syrian war on two fronts: the covert CIA-led campaign against the Bashar al-Assad regime and the overt, Pentagon-led military operation against the so-called Islamic State in Iraq & Syria (ISIS).

Matthew Ayton offers new insights into a dimension of US policy in Syria that has so far been given little analytical attention; the employment of what American strategists called the 'by, with & through approach' to ground warfare. This saw the US provide weaponry and training to non-state militias in an attempt to achieve strategic objectives without deploying large numbers of troops, in order to reduce blood-and-treasure costs, following the costly post-9/11 wars in Iraq and Afghanistan.

Drawing on a wealth of original interviews with American national security officials and the Syrians who worked with them on the ground, this book shows that despite being presented as a cost-saving panacea to intervention, this strategy came with significant - costly - and even deadly - consequences.