“The perception was that my credibility was at stake, that America’s credibility was at stake,” Obama explained. “And so for me to press the pause button at that moment, I knew, would cost me politically. And the fact that I was able to pull back from the immediate pressures and think through in my own mind what was in America’s interest, not only with respect to Syria but also with respect to our democracy, was as tough a decision as I’ve made—and I believe ultimately it was the right decision to make.”

Obama argued that, by going against the conventional wisdom, he was breaking the hold on American policymakers of what he called “the Washington playbook,” which he described this way: “It’s a playbook that comes out of the foreign-policy establishment. And the playbook prescribes responses to different events, and these responses tend to be militarized responses. Where America is directly threatened, the playbook works. But the playbook can also be a trap that can lead to bad decisions. In the midst of an international challenge like Syria, you get judged harshly if you don’t follow the playbook, even if there are good reasons why it does not apply.”

In the matter of the vanishing red line, Obama claimed ultimate victory in large part because the Russian president, Vladimir Putin, offered him a way out—in exchange for forgoing strikes on Assad regime targets, the Russians would convince the Syrians to give up their chemical weapons stockpiles. Huge stockpiles of chemical agents would subsequently be shipped out of Syria for destruction, and Obama’s allies explained the sagacity of his approach by noting that President George W. Bush went to war in Iraq to neutralize weapons of mass destruction that no longer existed by the time of the 2003 invasion; Obama, on the other hand, avoided war in Syria while somehow managing to neutralize its chemical stockpiles.

The events of the past week, culminating in the decision by President Obama’s successor to launch a punitive strike on a Syrian air base in retaliation for Assad’s continued use of chemical weapons against civilians, prove a number of points, some that reflect well on Obama, and some that do not. The first is that the 2013 Obama-Putin deal to disarm Assad of his chemical weapons was a failure. It was not a complete failure, in that stockpiles were indeed removed, but Assad kept enough of these weapons to allow him to continue murdering civilians with sarin gas. The argument that Obama achieved comprehensive WMD disarmament without going to war is no longer, as they say in Washington, operative.

The events of the past week also prove that a core principle of the Obama Doctrine is dead. President Trump’s governing foreign policy doctrine is not easily discernible, of course. His recent statements about Syria—kaleidoscopic in their diversity—combined with his decision to order an attack, have half-convinced me that he is something wholly unique in the history of the presidency: an isolationist interventionist.