This left US policy in a complete shambles: unwilling to act to change the military balance, yet unwilling to accept a rebel defeat. The focus increasingly turned to how to prevent the jihadi groups from becoming a source of terror both in the countries near Syria and in the countries from which they come — including a growing group from the US and Britain. ISIS will not conquer Iraq, but it has shown growing strength and demonstrated that the government in Baghdad and the Iraqi army are incompetent sectarian entities dependent on outside support. ISIS has also created a de facto alliance between the US and the Islamic Republic of Iran, both seeking to save Baghdad and stop the Sunnis — a disastrous alignment of interests that strengthens Iran and alienates all of the West's Arab allies in the Gulf.

Why did the President not act? Though fully aware of the magnitude of the crisis, in human terms and as a security problem, Obama has repeatedly rejected advice that might have contradicted the master narrative of the administration: that it has ended two wars and enmeshed us in no others. The fear, presumably, was that deep involvement in the Syrian civil war through covert aid to some rebel groups or air strikes on regime chemical weapons assets would bring the US into a battle, against jihadis and against Iran and Hezbollah, that might prove long, dangerous, and unsuccessful. In late May Secretary of Defense Chuck Hagel reiterated that if "the US tried to interject itself in a military way, that will only make it worse". Moreover, this policy debate has taken place against the backdrop of the President's decision to pull all American troops out of Afghanistan by the end of his administration. Deeper involvement in Syria would, logically, contradict the "no more war" message. So a fortiori would a return to military action in Iraq.

But in refusing to act, he has been isolated within his own administration. Obama's 2012 decision against sending military aid to the Syrian rebels was made despite the contrary advice of his then top national security officials, including Secretary of State Hillary Clinton, CIA Director David Petraeus, Joint Chiefs Chairman Martin Dempsey, and Secretary of Defense Leon Panetta. As the Washington Post put it, "President Obama has resisted advice from inside and outside his administration to abandon his passivity and do something to help Syria — not to send ground troops, the straw man his spokesmen regularly erect to fend off criticism, but rather to train and equip the rebels or help patrol a safe zone for them to evade Mr Assad's depredations." Obama's last-minute decision not to strike Syria in 2013 after its use of chemical weapons was popular in the Pentagon and with the public but clearly went against advice from Secretary of State John Kerry. In June 2013 the administration announced the provision of some military aid to the rebels, but from all the evidence little or no such assistance actually followed — so it cannot be said that there was a real policy change.

Finally in late May this year the President himself announced in his speech at West Point a decision to give additional aid to the rebels: "I will work with Congress to ramp up support for those in the Syrian opposition who offer the best alternative to terrorists and brutal dictators." This decision to aid the Syrian rebels followed months and indeed years in which defenders of Obama's inaction claimed that aid to the rebels would be pointless because they were too weak and were untrustworthy. But in June the former US ambassador to Syria, Robert Ford, who had been a special coordinator on Syria policy for the Obama administration, resigned from the Foreign Service saying that he "was no longer in a position where I felt I could defend the American policy". Ford was asked about the claim that aiding the rebels was almost impossible because we did not know whom to aid. He replied: "We've identified them quite well now. Some people say, well, we don't know them well enough; we can't depend on them. We know them quite well. We've worked with them for years." Why Obama rejected this view for years, and then reversed himself at West Point, remains mysterious.