Defense Secretary Robert M. Gates delivers a speech to the Security and… (John Thys / AFP/Getty Images )
Reporting from Brussels — In one of his last major addresses before his retirement this month, Defense Secretary Robert M. Gates said Friday that NATO's sometimes shaky air campaign in Libya had "laid bare" the shortcomings of the alliance, which he said was facing "collective military irrelevance" after years of inadequate defense spending by most of its members.
In March, the alliance unanimously backed the decision to go to war in Libya to protect civilians from forces loyal to Moammar Kadafi, but Gates noted that fewer than half of NATO's 28 members were participating in the military operation and fewer than a third are conducting airstrikes against ground targets.
FOR THE RECORD: Spending on NATO:
An earlier version of this article incorrectly said that NATO has set a target for its members to spend at least 4% of their gross domestic product on defense. The correct number is 2%.
"Frankly, many of those allies sitting on the sidelines do so not because they do not want to participate, but simply because they cannot," Gates said. "The military capabilities simply aren't there."
Photos: U.S. and allies attack Libya in March
The assessment of NATO's capabilities came at the end of an 11-day around-the-world trip that included stops in Asia and in Afghanistan, during which Gates said goodbye to U.S. troops after 4 1/2 years in office. A former CIA analyst, Gates has used the trip to review America's place in the world, including the state of the transatlantic security relationship that has been at the center of his four-decade-long career in government.
While praising NATO for its performance in Afghanistan, he said the alliance was suffering from shortcomings in "capability and will" in Libya, even though it is a "mission in Europe's neighborhood deemed to be in Europe's vital interest."
His remarks, to an audience of diplomats, military officers and former alliance officials at a Brussels library, came after two days of closed-door meetings with fellow defense chiefs at NATO headquarters, during which Gates was at times even more blunt about the alliance's other shortcomings, according to U.S. officials.
On Wednesday, he took the unusual stepping of criticizing Germany and Poland, which have refused to participate in the Libya campaign, along with Spain, Turkey and the Netherlands, which are participating but not in airstrikes, calling on them to step up their roles, according to officials familiar with the discussion.
The biggest problem, he said Friday, was that few countries had spent money on aircraft and other systems that deliver intelligence, surveillance and reconnaissance, which are critical to the air war in Libya. The NATO air operations center in Naples, Italy, is designed to oversee as many as 300 aircraft sorties every day, but it is handling only about 150 because of a lack of targeting specialists in non-U.S. NATO militaries.
The Pentagon has provided U.S. military personnel to make up the shortfall at the center, and has provided extra munitions to countries that are conducting airstrikes but are running short of ammunition.
"The mightiest military alliance in history is only 11 weeks into an operation against a poorly armed regime in a sparsely populated country -- yet many allies are beginning to run short of munitions, requiring the U.S., once more, to make up the difference," he added.
There was little immediate reaction to Gates' remarks from European officials, though several privately said he gave inadequate credit to the role alliance members are playing in the war in Afghanistan. Nor, one European official said, was it fair to blame other NATO members for the difficulties in Libya, given that the United States has taken a support role in the conflict.
After leading the initial air assault on Libya in the first weeks of the war, the United States scaled back its involvement and is now mostly providing aerial refueling, surveillance and other support functions, as well as several Predator drones, which are being used in airstrikes.
In recent weeks, the U.S. has stepped up its involvement by providing nine additional refueling aircraft, according to a senior American official.
Gates praised the role of Norway and Denmark in Libya ,saying they had provided 12% of the strike aircraft for the operation but had carried out about a third of the airstrikes.
Even after years of Washington's public and private pressure on NATO allies to increase military spending, Gates conceded that there was little prospect of that happening, especially with the intense fiscal pressure many governments in Europe now face.
He called instead on NATO countries to allocate their limited military budgets more wisely, on weapons and other capabilities that complement, rather than duplicate, spending by other members of the alliance.
Gates said that the U.S. share of NATO military spending has risen to more than 75%, while there are only four other members of the alliance -- Britain, France, Greece and Albania -- whose military spending now exceeds 2%, the target set by NATO.
As a generation of American leaders whose outlooks were not formed during the Cold War come to the fore, Gates warned that there would be "dwindling appetite and patience" for the U.S to expend funds on nations "apparently willing and eager for American taxpayers to assume the growing security burden left by reduction in European defense budgets."