Well, okay, our headline goes too far. But the claim is about as plausible as Rand Paul’s outburst that Republican internationalists like Lindsey Graham and John McCain are responsible for the rise of the Islamic State…

Mr. Paul is intelligent enough, and his misreading of recent Middle Eastern history is so flagrant, that he might be trying to deflect attention from his own misjudgments. In Mr. Obama’s second term, the U.S. has largely followed Mr. Paul’s foreign-affairs preferences to the letter, and the result has been more chaos and disorder.

The origins of the Islamic State are al Qaeda in Iraq, or the post-Saddam Hussein insurgency that suffered a near-total defeat amid General David Petraeus’s surge and the Sunni Awakening. The weak guerilla remnants of that organization survived on the peripheries of Iraq and Syria between 2008 and 2011 and then filled the security vacuum that Mr. Obama left behind by withdrawing all U.S. forces.

The Islamic State’s revival was also aided by its sanctuary over the border in Syria as that country revolted against the rule of Bashar Assad. Far from supplying arms to the rebels, Mr. Obama explicitly rejected U.S. intervention in 2011. CIA Director Petraeus and Secretary of State Hillary Clinton again advocated aiding the rebels in 2012, but Mr. Obama refused again.