A few factors, including the breakdown of peace talks between the Syrian opposition and the Assad regime, the Assad regime’s territorial gains of late, and the slow pace at which the regime is giving up its chemical weapons has some in Washington wanting the U.S. to get more involved in supporting the Syrian rebels, according to the Wall Street Journal. But the Pentagon is raising concerns:

Frustrated by the stalemate in Syria, Secretary of State John Kerry has been pushing for the U.S. military to be more aggressive in supporting the country’s rebel forces. Opposition has come from the institution that would spearhead any such effort: the Pentagon.

Mr. Kerry and United Nations Ambassador Samantha Power have advocated options that range from an American military intervention to weaken the regime of President Bashar al-Assad to using U.S. special operations forces to train and equip a large number of rebel fighters. Such moves would go far beyond the U.S.’s current engagement.

In recent White House meetings, Chairman of the Joint Chiefs of Staff Gen. Martin Dempsey and Defense Secretary Chuck Hagel have pushed back against military intervention, said senior officials.

They argue that the risk of being dragged into what both men see as an open-ended foreign entanglement.

Both sides have agreed on the need to create an expanded program to train and equip moderate Syrian rebels. But the Pentagon worries the Assad regime would halt cooperation on the removal of chemical weapons if the military training starts now. Officials said Mr. Kerry has agreed to that delay.

Correlation is not causation, but since the deal was reached between the U.S. and Russia and Syria to remove the country’s chemical weapons, Assad hasn’t exactly seen his position eroded.

Whatever the legitimacy of the chemical-weapons concern, the Journal’s story makes clear that the military brass — especially General Dempsey, the chairman of the joint chiefs — just doesn’t like the idea of intervention, period, saying they worry about getting embroiled in another Middle Eastern conflict. 

But is there more at work here? There are both practical and principled reasons to worry about the feasibility of cooperation with the rebels, assuming direct intervention is off the table in everyone’s minds: For months and months now, it’s been obvious that the effective parts of the Syrian opposition are militant Islamists and the Western-friendly international representatives of the rebels are powerless.

A long ways back, perhaps the situation could have been different, but now almost all the effective opposition groups work with al-Qaeda’s Syrian franchise, if they’re not just hardline al-Qaeda-linked groups themselves. They’ve done that in part, surely, because some of them are ideologically sympathetic, but they’ve also done it to stand a chance against the regime — and a splinter terrorist group that’s too brutal even for al-Qaeda.

So if the U.S. did want to scale up the CIA’s very small training and equipping program in Syria, it’s quite possible that Islamists have such influence that we don’t have any remotely palatable partners for such an operation, besides geographically marginal (and therefore not that useful) Kurdish groups. You might recognize this problem from some other Middle Eastern entanglements.