Through six months of war in the skies over Libya, the Obama administration has had one big, fat red line: it won’t put any troops on the ground. Except that red line turned out to be permeable, as CIA operatives made their way to the shores of Benghazi. And as the fall of Tripoli turns into a battle for the city, NATO isn’t closing the door on sending western peacekeeping forces to Libyan soil.

During a press conference on Tuesday in Brussels, NATO spokeswoman Oana Lungescu assured that there will be “no NATO troops on the ground in the future.” Only Lungescu left herself some wiggle room. Should the United Nations or Libyan revolutionaries request it, NATO “is willing to help in a supporting role,” she said, without elaborating.

That’s consistent with NATO’s attitude from the start of the war. Adm. James Stavridis, NATO’s military chief, testified to Congress in March that the “possibility of a stabilization regime exists” after Moammar Gadhafi’s downfall.

But if NATO capitals (Paris? London?) might think about putting boots on the ground, Washington is loudly saying it wants no part. Leon Panetta, the secretary of defense, promised reporters on Monday that the U.S. was “not at all” considering any ground troops. A host of administration officials lined up to echo that sentiment, emphasizing the need for Libyans to oust Gadhafi themselves. (Even as NATO warplanes screamed overhead.)

Still, the large-scale absence of U.S. ground forces hasn’t been much of a problem for NATO during the war. France and Britain deployed special operations forces to turn the Libyan rebels into disciplined soldiers. NATO maintains an official fiction that it’s not “tactically” aiding the rebels, as Col. Roland Lavoie, another alliance spokesman, said Tuesday — all the while assuring Gadhafi loyalists that NATO retains “precision munitions [that] allow us to take targets… we have the capability to do so, and believe me, we will do so.” It’s possible that NATO members could send peacekeepers even without a NATO mandate.

And there may not be much peace to keep in the near term. Fighting is intensifying in Tripoli: Gadhafi’s son Seif emerged defiant hours after rebels announced they had captured him, and Moammar Gadhafi is himself still at large. “The only victory will be when Gadhafi is captured,” said Mustafa Abdul Jalil, the head of the rebel governing council.

Or even after that. Loyalist forces are heading to Gadhafi strongholds of Sirte and al-Jafra in the south. One of the biggest mysteries of the battle for Tripoli is why the allegedly potent “Khamis Brigade,” commanded by one of Gadhafi’s sons, didn’t put up much of a fight on Sunday. It’s possible that the brigade melted away to fight a guerrilla war, as Saddam Hussein’s Republican Guard did in 2003.

There would be no shortage of weapons for that fight. Rockets, rifles and missiles — including intimidating SA-7 surface-to-air missiles — are everywhere in Libya. (Even if they’re not exactly quality weapons.) Gadhafi planted landmines along the eastern roads as a deadly present for the revolutionaries. Militias with dubious loyalties have already sprouted up where Gadhafi’s rule has fallen. And Gadhafi still has unsecured stockpiles of chemical weapons.

Put another way: even if the worst case scenarios of a Gadhafist insurgency don’t materialize, there’s no shortage of destabilizing factors in post-Gadhafi Libya. It’s a lot to put on the shoulders of a fractious rebel government — which, in fairness, deserves credit for avoiding chaos in areas like Benghazi that it’s controlled for months.

But destabilization is precisely what drives calls for escalation. Already, pundits like Richard Haass, a Bush administration official who runs the Council on Foreign Relations, is urging President Obama to “reconsider his assertion that there would not be any American boots on the ground; leadership is hard to assert without a presence.” That’s exactly why Panetta’s predecessor, Robert Gates, wanted the U.S. out of Libya ASAP.

NATO is hardly getting out. Lavoie pledged on Tuesday that since Gadhafi’s forces “give no sign to stop terrifying the population,” the air war will continue. “Pieces of artillery, radar sites” and other targets in and around Tripoli will still be targeted, Lavoie said, even waving away the non-capture of Gadhafi by saying, “I’m not sure it really does matter.” Left unsaid was when NATO’s war in Libya can actually end, even if Gadhafi’s rule is well and truly finished.

Photo: al-Jazeera