It’s possible that the Yemeni government — which, as Brennan said, has had some success reclaiming territory in the south from AQAP — will get sufficiently capable under U.S. military tutelage. But it’s also possible that Yemen’s counterinsurgency efforts will proceed unevenly, creating pressure for the U.S. to draw itself in deeper, having made expansive promises about mitigating seemingly intractable problems about water, healthcare and economic development. That’s exactly what happened in Iraq and Afghanistan, where wars undertaken for discrete objectives bloated into lengthy, expensive nation-building efforts. And at least in those interventions, the U.S. admitted it was at war.