In the near term, administration officials expressed cautious optimism that the combination of more U.S. air power, a bigger Iraqi push against Islamic State forces in Ramadi along with Kurdish and Syrian Arab efforts in Raqqa and along the border could shift the momentum on the battlefield.

So far, it’s a strategy that hasn’t draw much support in Washington. Republicans and some Democrats, who have been pressing Obama to do more, criticized the president’s caution.

“His incremental step-by-step approach is an effort to manage risk and keep tight reins on the mission, but ultimately it could mean that the whole is less than the sum of its parts,” said Michele Flournoy, the chief executive officer of the Center for a New American Security, who was among Obama’s top choices to be defense secretary last year before Carter was selected.

Flournoy said the addition of U.S. air controllers to call in airstrikes and Apache helicopters, combined with the measures the president is already taking, could accelerate gains on the battlefield.