BRUSSELS Plans to send attack helicopters to Libya and intensified bombing of Tripoli reflect growing Western worries that the war is dragging on indecisively but may not be enough to tip the balance quickly.
On Tuesday, NATO warplanes hammered Libyan leader Muammar Gaddafi's compound with their heaviest air strikes yet on Tripoli after the United States said he would "inevitably" be forced from power.
But despite early optimism that Western intervention would quickly help topple Gaddafi, after three months of fighting and two months of Western airstrikes, there is little evidence to suggest his government is on the verge of collapse.
Reflecting growing Western frustration, France announced on Monday that it and Britain would deploy attack helicopters to achieve more accurate strikes on Gaddafi's forces -- though Britain on Tuesday it has yet to decide on such a move.
Analysts say deploying helicopters would mark a significant escalation as well as an increase in risk, as while they would make it easier to hit urban or embedded targets with precision, they would also be more vulnerable to ground fire.
"Starting with the introduction of military advisers, the introduction of drones onto the bombing of Tripoli, it reflects a movement up the ladder of escalation," said Shashank Joshi of London's Royal United Services Institute think tank.
"It shows France and Britain are increasingly concerned about this hardening from the stalemate that exists presently into something intractable.
"What's guiding them is a real fear of it degenerating into the Iraqi no-fly zone of the 1990s in which they committed to indefinite open-ended expensive operations because of their own moral and political commitment to the rebels."
Military analysts French Tigre and Gazelle helicopters, and the U.S.-built Apache flown by the British, would be a big help in protecting rebel areas such as Misrata.
"The downside is helicopters flying at comparatively low level are at greater risk, especially to shoulder-fired
missiles which fixed-wing aircraft have been lying well out of the range of," said Douglas Barrie of the International Institute for Strategic Studies.
RISK OF CASUALTIES, CAPTURE
Until now, the NATO-led effort in Libya has suffered no combat casualties, and the main concern of Western governments has been to justify the mounting costs of the mission at a time of economic austerity, which has already ensured that the United States has taken a backseat.
Deploying helicopters not only increases the risk of casualties, but also the possibility of crews being taken prisoner if they are shot down, helping to explain why they were not used earlier in the campaign.
"You may imagine there were people in various governments hoping that attacking the regime's command-and-control infrastructure, heavy artillery and air force was going be enough to make Gaddafi leave power," Barrie said.
"That was always optimistic. He hasn't hung around for 42 years without being bombed on a couple of occasions and he shows no inclination to leave the country as of yet."
While the two-dozen helicopters envisaged may not end up being game-changers in themselves, they would ratchet up the pressure on Gaddafi and give psychological boost to the rebels.
"A helicopter in your operations area is a more-or-less continuous presence. It has a coercive effect on opposing forces and conversely should bolster morale of the rebels," Barrie said.
Joshi said it would also be an important demonstration of Western resolve.
"The psychological side of this is significant and in line with the bombing of Tripoli," he said.
"Bombing Tripoli says the war will be taken to Tripoli -- you are not exempt, and the helicopters say we are willing to take great risks and our resolve is not to be taken lightly."
At the same time, as time ticks on Western leaders will see themselves under mounting pressure.
French Foreign Minister Alain Juppe said in parliament on Tuesday: "I can assure you that our will is to ensure that the mission in Libya does not last longer than a few months."
Analysts point to the run-up to elections in France and in Libya's neighbor Egypt and time limits set by some NATO states on their participation in the mission, and well as concerns in Britain about mounting costs at a time of defense cuts.
Some Egyptian election candidate will inevitably seek to win support by criticizing NATO's intervention in an Arab country and the more the campaign goes on the greater the risk of it becoming detached from its original Arab support base.
"This is not something that's going to be finished in weeks. Diplomatically, politically, economically and militarily the regime is not strong, but it's strong enough to endure," Joshi said.
"NATO is very strong, but not strong enough to land the decisive blow, so this can go on well into the summer. There isn't a concrete deadline by which it needs to be wrapped up, but there is a sort of looming anxiety that this could drag on."