BRUSSELS (Reuters) - For a man who has been under Western bombardment for more than three months, Libyan leader Muammar Gaddafi has not appeared unduly worried.
His appearance playing chess at the weekend with the Russian head of the World Chess Federation, Kirsan Ilyumzhinov, was a piece of psychological theater worthy of a veteran campaigner.
While Gaddafi has seemed to keep his cool, despite a relentless bombing onslaught launched in March, it is his powerful opponents in NATO who have appeared to lose theirs.
Reflecting frustration at NATO's inability to achieve quick results in a campaign some had forecast would be over in days or weeks, the U.S. defense secretary rounded on European allies last week for failing to back the mission the alliance took over in late March.
"The mightiest military alliance in history is only 11 weeks into an operation against a poorly armed regime in a sparsely populated country," Robert Gates said, "yet many allies are beginning to run short of munitions, requiring the U.S., once more, to make up the difference."
Now it's not only bombs, but the planes to deliver them that NATO risks running short of, with no sign of any new commitments to sustain the mission despite dire warnings from Gates about the very future of NATO and direct appeals to defense ministers from alliance Secretary-General Anders Fogh Rasmussen.
While Rasmussen has expressed his hope that the Libya mission can be concluded before the end of a second 90-day operations cycle in late September, many analysts consider this wishful thinking, given Gaddafi's resilience.
A mission that drags on beyond that date could present major problems, with some allies already stretched in their commitment and the United States reluctant to get dragged back into a leading role in the conflict as President Barack Obama faces criticism for the mission in the U.S. Congress.
Only eight of the 28 NATO states have provided planes for strike missions in Libya and pressure by Gates on others with available resources to do so, such as Spain, the Netherlands, Turkey and Germany, appear to have fallen on deaf ears.
Already Norway has announced it will have to scale back its contribution of strike aircraft this month and end their role in August, while European NATO stalwart Britain has said continuing the mission beyond September could be a challenge that could require diversion of resources from elsewhere.
Analysts say this could mean from NATO's war in Afghanistan, still termed the alliance's number-one priority.
Worse looms over the horizon, with France indicating it will need in the autumn to withdraw the Libyan mission's only aircraft carrier, the Charles de Gaulle, on virtually continuous operations since last year -- with no replacement in the offing.
ELEPHANT IN THE ROOM
"The elephant in the room is the imminent departure of the French carrier, given it has been flying 30-40 percent of all NATO strike sorties," said Tim Ripley, of Jane's Defense Weekly.
"It's a looming problem, so sustaining this operation, particularly if it's going to grind past September or October, is going to be a problem."
In the absence of other allies coming forward with strike aircraft that could be flown from land bases -- which would necessitate a fleet of refueling tankers only the United States could provide -- one radical solution would be for Britain to redeploy decommissioned Harrier aircraft to its carrier HMS Illustrious, which was designated for conversion into a helicopter ship in Britain's defense review.
However, even if such a tricky political decision were taken by British Prime Minister David Cameron, it would be up to four months before the ship was ready for action, Ripley said.
A senior NATO commander conceded the extent of the worry on Tuesday. French General Stephane Abrial said the Libyan crisis had come as "a surprise" and if it were to last a long time "the resources issue will become critical."
Douglas Barrie, a military aviation specialist at London's International Institute of Strategic Studies, said that when Western powers launched the war in March, they appeared to be anticipating a quick mission.
"There may have been the view they would be pushing on an open door, but as the campaign has developed, it's become apparent that Gaddafi is not simply going to hang up his hat and leave the country," Barrie said.
"There was this aspiration that the mission would lead to the collapse of the regime and Gaddafi's removal but it wasn't structured to deliver that.
"And one of the things about Gaddafi is that he's stayed in power through thick and thin for four decades plus. He's been bombed before and has a track record of being able to hang in there in difficult circumstances."
Analysts said that in the absence of an unlikely "lucky bomb" that killed Gaddafi, and given the limitations of rebel forces and the West's unwillingness to commit ground forces, a divided Libya appeared an increasingly likely outcome.
"I wouldn't be surprised if NATO had to be there for a year, and I think it's 50-50 whether we end up seeing a frozen conflict and a de facto partition, with Gaddafi controlling part of Libya and the rebels the other," said Chris Schnaubelt of the NATO Defense College in Rome.
"If Gaddafi gets killed, then all bets are off, but if he survives physically, you are not going to get a quick change in the situation."
Marko Papic of political risk consultancy Stratfor said there appeared to be a growing acceptance of such a solution, at least in European capitals.
"It seems that they don't need to see the whole of Libya under rebel control -- this doesn't seem something they need success on for political, domestic purposes and that a split Libya is perfectly fine for the moment.
"Libya is not something that would make or break a government, the euro zone crisis and austerity are much more important politically," Papic said.
"In Libya, there's no political cost to muddling through indecisively."
(Editing by Alistair Lyon)