The skepticism is more complex than the hard-line opposition of many liberals a decade ago when President George W. Bush launched a military campaign in Iraq with heady expectations. Today, liberals seem open to Obama’s appeals to provide aid to religious minorities who he says are victims of genocide. But — among this set of lawmakers — that doesn’t translate into support for significant military intervention.

Rep. John Garamendi (D-Calif.), one of the biggest anti-war advocates on the Hill, said in an interview Friday he was concerned the airstrikes could signal broader U.S. involvement, and urged Obama to have a “very, very clear definition” of the United States’ goals in Iraq.

“We are on a slippery slope,” said Garamendi, a member of the House Armed Services Committee. “Where this ends, I don’t think any of us know. But the president has to be very, very clear about timing and purpose. Thus far, it’s insufficient from my point of view.”