After last night’s speech, Barack Obama had to hope that the rebels in Libya would keep the momentum as leadership for the Western intervention changed hands, at least nominally.  Instead, both Reuters and CBS report this morning that government forces have begun pushing rebels back east after a few days of falling back, and that the rebel retreat looks more like a rout.  In fact, it looks like the government may be picking up popular support:

Muammar Gaddafi’s better armed and organized troops reversed the westward charge of Libyan rebels as world powers gathered in London on Tuesday to plot the country’s future without the “brother leader.” …

Later, a hail of machinegun and rocket fire hit rebel positions. As the onslaught began, rebels took cover behind sand dunes to fire back but gave up after a few minutes, jumped into their pick-up trucks and sped off back down the road to the town of Bin Jawad. Shells landed near the road as they retreated.

Without air strikes it appears the rebels are not able to hold ground or make advances. The battle around Sirte, Gaddafi’s birthplace, will show if the rebels have reached their limit.

Reports from retreating rebels that some residents outside Sirte fought alongside government troops are an ominous sign for world powers hoping for a swift end to Gaddafi’s 41-year rule.

CBS called the retreat a “panicked scramble”:

Libyan government tanks and rockets blunted a rebel assault on Muammar Qaddafi’s hometown of Sirte on Tuesday and drove back the ragtag army of irregulars, even as world leaders prepared to debate the country future in London.

Rockets and tank fire sent Libya’s rebel volunteers in a panicked scramble away from the front lines, suggesting that the opposition is still no match for the superior firepower and organization of Qaddafi’s forces, despite an international campaign of deadly air strikes. ….

Tuesday’s shelling and the undisciplined volunteers’ disorganized flight in their pickup trucks, however, showed that the rebels’ fundamental inability to counter Qaddafi’s heavy weapons without extensive outside help.

It’s also disturbing that Gaddafi seems to be successful in recruiting his own militias.  They come from his power base, of course, and it’s not a great surprise that Sirte residents won’t be happy to see rebels take out their vengeance on their city.  Don’t be surprised to see Gaddafi try to focus media attention on his own “grassroots” support.

That opens a serious political risk for Obama, as all of the news agencies now routinely report that the only reason the rebels advanced this far was because of air strikes from the US and its coalition.  If the rebels cannot hold ground against the much-more disciplined government forces without allied air cover, that tends to discredit the notion that we are only enforcing a UN mandate and not intervening on their behalf.  If Gaddafi triumphs, the West will look weak; if the rebels can stall Gaddafi’s forces — which looks less likely without significantly increased air attacks — then we will have set Libya up for a long, bloody civil war, one which will create all of the failed-state conditions that serve as breeding grounds for radical Islamist terror groups.

If the West wants to avoid those outcomes, they will have to commit far more resources and work more openly on behalf of the rebels to do so, which will end up violating the UN mandate.  John McCain wants an all-out effort to topple Gaddafi, which sounds extreme but actually diagnoses precisely the predicament in which the US finds itself now.  If we’re not prepared to force regime change in Libya now that we’ve very obviously committed ourselves to it by helping the rebels advance, then we should get out — and shouldn’t have gotten involved in the first place.