While uncertainty prevails in Libya, the breakthrough that brought rebel forces to the heart of Tripoli shows rumors of NATO's demise may have been premature.
The Atlantic alliance dismissed as having a "dismal future" by former U.S. Defense Secretary Robert Gates has proven a vital role in bringing Moammar Gadhafi's regime to the brink of collapse.
"NATO was in need of a success, and it seems that in Libya it will get one," said Daniel Korski, a European Council of Foreign Relations specialist. A day earlier, U.S. President Barack Obama said NATO had "once more proven that it is the most capable alliance in the world."
But analysts also say the Libya effort has laid bare challenges for NATO _ including internal policy disagreements _ at a time when many of its members are facing tight state budgets and wary public opinion about foreign wars.
NATO declared on Tuesday that it remains in the fight to the end, as fighting erupted around Gadhafi's main military compound in the capital, hours after the stunning appearance by Libyan leader's son and heir apparent to repel rebel claims he had been captured.
The morale boost for Gadhafi loyalists and the ferocity of Tuesday's fighting raised the prospect of a protracted battle for Tripoli.
But with rebels entrenched in the capital, many international leaders and diplomats are turning their attention to the era after his 42-year rule.
"It's vindication for NATO ... There were a lot of critics out there," said Nicholas R. Burns, the U.S. ambassador to NATO between 2001 and 2005, who now teaches at Harvard's John F. Kennedy School of Government.
"It took much longer than anybody thought, but I think that's a minor point when you see the final result _ the imminent victory of the rebel army against Gadhafi's forces because NATO made the decisive difference."
While the apparent end-game came with startling speed, the length of the NATO campaign also points to NATO's limitations. Many Western leaders had predicted Gadhafi's fall within days or weeks after the air campaign began March 19. Instead, it's taken six months _ and Gadhafi is still at large.
Until a rebel breakthrough in recent weeks, the opposition National Transitional Council seemed on the brink of collapse in late July after the mysterious killing of its military chief, Abdel-Fattah Younis _ raising concern that the campaign would drag on.
"After some spoke of a stalemate, I remind you that in six months _ apparently _ we'll have reached our goal," said French Foreign Minister Alain Juppe. "We've shown determination, and discernment."
While NATO led the operation, with support from nonmembers like tiny Gulf state Qatar, it was mainly a French and British show backed by critical U.S. support _ notably drone strikes and round-the-clock air surveillance.
NATO members face a vote next month on whether to issue a second three-month extension of the Libya mission. Some complain it has siphoned off resources from NATO's main mission: the 10-year war in Afghanistan.
Britain and France, western Europe's biggest military powers, alone accounted for three-fourths of NATO air operations in Libya, Juppe said Tuesday. Only eight of NATO's 28 members participated. Norway pulled out weeks ago, Italy reduced its role, and several others were planning to do so.
"While the alliance should definitely be pleased about its role there, there are still some important questions to be asked," said Korski, alluding to the predominant French, U.S. and British role and reliance on the rebels.
"The campaign has again exposed a long-term truism _ NATO remains incredibly reliant on U.S. assets, U.S. command and control arrangements, U.S. intelligence equipment and so on," he said.
Also in September, the U.N. General Assembly is due to debate the airstrikes, with many members blaming NATO for overstepping the limited intent of the U.N. mandate in March that authorized a no-fly zone and the protection of civilians caught up in the civil unrest.
That puts NATO in a tricky position: While many member governments called for the ouster of Gadhafi, its U.N. mandate didn't call for targeting him. Alliance officials repeated Tuesday that he wasn't being fired upon.
Francois Heisbourg, an adviser to the French Defense Ministry who heads the Foundation for Strategic Research in Paris, said NATO's Libya has exposed good points and bad in the alliance.
On the positive side, he said NATO's campaign broke from American war-making in recent history because infrastructure like electricity grids, water purification plants, and many oil refineries were largely left intact _ unlike in the Balkans, where some bridges destroyed by the allied forces in the '90s even today haven't been rebuilt. That could make for a smoother Libyan transition to a post-Gadhafi era, Heisbourg said.
He marveled in particular at the relative lack of collateral damage in the more than 7,500 air strike sorties that NATO says it has conducted in Libya _ calling it "nothing short of a miracle."
But Libya also exposed two key challenges for NATO, he said.
The first centers on Germany's unwillingness to commit its forces in Libya _ notably AWACS aerial early warning planes that were supposed to be under NATO command, not subject to political orders in Berlin.
"(The fact) that an 'integrated NATO' really has no meaning, has some really serious consequences," he said. "In effect Germany's progress toward military normality have been turned back about 20 years."
The other, he said, was America's show of "leading from behind" _ with Washington's insistence early on during the conflict that it would not take an operational lead or participate in front-line combat operations.
For decades, the alliance has depended on U.S. close-air support from low-flying, armor-busting aircraft like the A-10 Warthog, which Washington pulled out from Libya's skies early on, he said.
"This is the first time in 50 years that the U.S. has made that sort of choice. The question is: Will America now consistently lead from behind, in a number of military operations, is this a new pattern?" Heisbourg said.
"If it is, the Europeans are going to have to invest in areas of defense they hitherto had no need to invest in, and that means that scarce resources will have to be drawn to those areas _ at the expense of other capabilities," he said.
That echoed concerns expressed by former Gates in a speech in Europe in June, shortly before leaving his post, pointing to a "real possibility of collective military irrelevance" at NATO and urging members to look at ways of improving procurement, training, logistics and sustainment.
At the time, Gates criticized the alliance for running short of munitions only 11 weeks into the campaign "against a poorly armed regime in a sparsely populated country" _ and requiring the U.S. to make up the difference.
Harvard's Burns said he agreed with Gates: "If there is one lesson to be drawn from this, it's that the major European countries need to invest more aggressively in modernizing their militaries."
But Heisbourg said that at a time of dwindling defense budgets and tight state finances _ such as the one exposed by the debt-ceiling debate earlier this month in Washington _ NATO must decide if it wants to be able to fight short-term wars near Europe, or far-flung, long-term wars like Afghanistan.
That, along with dissension among NATO members, presents key issues for the future _ even if the Libya campaign winds down soon.
"For the time being everybody will be smiling and happy, but those underlying problems will not be addressed," Korski said.
Lekic reported from Brussels.