“I know he talks about a 40-country coalition — is it a papier-mâché coalition, or is it for real?” Sen. Jon Tester (D-Mont.) said Tuesday. “Are these guys putting the same kinds of resources that we are? … I asked those questions; I did not get an answer.”

When asked about the plan to aid the Syrian rebels, Tester added: “If we’re talking about throwing additional dollars, we need to know where it’s going, we need to know who is paying for it, we need to know if it’s just flat going on the debt.”

The White House has requested $500 million as part of the program to train Syrian rebels, though the House plan does not appropriate those funds, instead relying on overseas contingency money to pay for the program. But as the military conflict carries on — potentially, for years — the president will almost certainly have to come to Congress eventually, either seeking a formal authorization for war or for a supplemental funding request that could cost into the billions. It could be a heavy lift.