When the United Nations authorized the Libya war on March 17, it balked at allowing foreign ground troops into the country. But its vague language and broad commitments to protecting Libyan citizens besieged by Moammar Gadhafi led many to wonder if the mission would expand. A month later, the first wave of foreign ground troops will enter Libya, as “advisers.” But the Libyan rebels are already asking for more than that.

Rebels opposed to Muammar Gaddafi calling for more western intervention in the besieged Libyan city of Misrata on Monday. (Photograph: Odd Andersen/AFP/Getty Images) The advisers aren’t from the United States. They’re from France and Britain, both of which are more gung ho than the U.S. is to escalate the Libya war. Still, both nations say they’re sending only small numbers of advisers to Benghazi, the rebel capitol, to professionalize a rebel force that badly needs training if it means to turn back Gadhafi’s military. On top of that, the European Union is preparing to send armed guards to accompany humanitarian aid to Libyan civilians.

It was surely inevitable. NATO’s air strikes haven’t stopped the loyalist attacks. If anything, they’ve opened up a gap in the alliance, as France and Britain criticized NATO for committing to the war insufficiently. With a stalemate on the ground, the U.S., France and Britain explicitly announced on Friday for the first time that the war will continue until Gadhafi is gone — even while they maintained that the military mission isn’t to overthrow him. The next step had to be some kind of aid on the ground.

The United States insists it won’t follow France and Britain down that road. President Obama pledged not to send ground troops into Libya. Defense Secretary Robert Gates, fearing mission creep, publicly warned against training the rebels.

But it’s sent CIA operatives to Libya to liaise with the opposition. And Obama has authorized giving the rebels $25 million in “nonlethal aid,” including “vehicles, fuel trucks and fuel bladders, ambulances, medical equipment, protective vests, binoculars, and non-secure radios.”

The rebels want a lot more. Their emissary to Washington wants NATO to destroy Gadhafi’s military. And while the rebels once ruled out foreign ground forces themselves — desiring the glory of overthrowing Gadhafi — now they’re reconsidering. “[T]hat was before we faced the crimes of Gaddafi,” a member of Misurata’s governing committee told reporters. With Misurata suffering under a two-month siege that’s getting worse, “we need a force from NATO or the United Nations on the ground now.”

At its most expansive, NATO has only imagined a presence on the ground in Libya in the form of a post-conflict peacekeeping force. But now western powers are setting foot on Libyan soil. The U.N. hasn’t sanctioned anything that smacks of an “occupation” force. But now that they’re helping to organize the rebels and committing to overthrow Gadhafi, can the westerners stop short of joining the fight on the ground?