Back in June, I warned libertarians with a yen for Paul that they “will doubtless get heartburn at many steps along his path striving for the GOP presidential nomination.” This was perhaps his biggest gut punch yet.

Libertarian noninterventionists had reason to expect better. As recently as June, the senator was sticking his neck out in the Wall Street Journal to stress how interventionist mistakes of the past on the part of both Obama and Bush have set the grim stage for Iraq’s current crisis. He also recognized that jumping back in to Iraq “would likely require another decade of U.S. presence and perhaps another 4,000 American lives—a generational commitment that few Americans would be willing to make.”

Even now, Paul has not said he’s ready for that decade of commitment. (Caginess about what he’d specifically do as president is, to Paul, a diplomatic virtue in and of itself. He’s used that as an explanation for why he doesn’t want to specify whether he thinks a potentially nuclear Iran can be contained or must be stopped at all military costs.)