A commitment of that nature would almost certainly require U.S. combat forces to deploy — some to help train foreign armies but others to man the front. U.S. forces are generally more highly trained than Gulf armies, especially with regard to high-skill missions such as rapid armored maneuvers, special operations, logistics, reconnaissance and close-air support. “We can provide capability on the ground the Arab world doesn’t possess,” Graham says.

There are several obvious drawbacks to such a plan. It would be highly controversial and might not even draw strong support from Republicans. The Pentagon might resist too, since it usually objects to joining any coalition it doesn’t control. Graham is an Air Force reservist who has spent 33 years on active and reserve duty in the Judge Advocate General Corps, which gives him more credibility on national security matters than others with no military background. Still, many Americans would probably object to sending U.S. troops into another intractable Middle East conflict, after more than 4,400 died in Iraq.

If military force did remove Assad, there’d still be the problem of whom to replace him with, lest Syria become another lawless state, similar to Yemen or northern Iraq, ripe for occupation by the Islamic State or other offshoots of Al Qaeda. “You’d have to get a political coalition to rebuild Syria,” Graham acknowledges. Easier said than done.