NATO has turned into a two-tiered alliance of members who consume security and those who produce it, Defense Secretary Robert M. Gates said here today. Gates spoke to NATO’s Security and Defense Agenda assembly the day after a meeting of the alliance’s defense ministers concluded.

“In the past, I’ve worried openly about NATO turning into a two-tiered alliance between members who specialize in ‘soft’ humanitarian, development, peacekeeping and talking tasks and those conducting the ‘hard’ combat missions — between those willing and able to pay the price and bear the burdens of alliance commitments, and those who enjoy the benefits of NATO membership, be they security guarantees or headquarters billets, but don’t want to share the risks and the costs,” the secretary said.

“This is no longer a hypothetical worry,” he added. “We are there today. And it is unacceptable.”

To be sure, Gates said, NATO is heavily involved in Afghanistan, and the troops assigned to the NATO-led International Security Assistance Force are acquitting themselves well.

“Consider that when I became secretary of defense, there were about 20,000 non-U.S. troops from NATO nations in Afghanistan,” Gates said. “Today, that figure is approximately 40,000. More than 850 troops from non-U.S. NATO members have made the ultimate sacrifice in Afghanistan. For many allied nations, these were the first military casualties they have taken since the Second World War.”

NATO took over ISAF four years ago, Gates noted, adding that he never would have expected the alliance to sustain this operation for this long, much less add significantly more forces in 2010.

“It is a credit to the brave ISAF troops on the ground, as well as to the allied governments who have made the case for the Afghanistan mission under difficult political circumstances at home,” the secretary said.

The coalition forces in Afghanistan now include 100,000 American service members who provide needed resources for a war that had been chronically underfunded due to operations in Iraq, Gates said. “These new resources – combined with a new strategy – have decisively changed the military momentum on the ground, with the Taliban ejected from their former strongholds,” he added.

But nothing remains static, he told the assembly, and as part of the plan to turn security control over to the Afghan government by the end of 2014, President Barack Obama soon will announce the size and pacing of the U.S. troop drawdown beginning in July. No matter what it is, Gates said, there will be no rush to the exits.

“The vast majority of the surge forces that arrived over the past two years will remain through the summer fighting season,” he said. “We will also reassign many troops from areas transferred to Afghan control into less-secure provinces and districts.”

The Taliban will attempt to counterattack, he said, but they will lose. And keeping the pressure on them will create a chance to bolster military success with governmental and economic success, he added.

“Given what I have heard and seen – not just in my recent visit to Afghanistan, but over the past two years – I believe these gains can take root and be sustained over time with proper allied support,” the secretary said. “Far too much has been accomplished, at far too great a cost, to let the momentum slip away just as the enemy is on his back foot.”

NATO cannot afford some troop-contributing nations to pull out their forces on their own timeline in a way that undermines the mission and increases risks to other allies, Gates said.

“The way ahead in Afghanistan is ‘in together, out together,’” he said. “Then our troops can come home to the honor and appreciation they so richly deserve, and the transatlantic alliance will have passed its first major test of the 21st century.”

But NATO operations in Afghanistan have exposed serious alliance shortcomings in military capabilities and in political will, Gates said. “Despite more than 2 million troops in uniform – not counting the U.S. military – NATO has struggled, at times desperately, to sustain a deployment of 25,000 to 45,000 troops — not just in boots on the ground, but in crucial support assets such as helicopters; transport aircraft; maintenance; intelligence, surveillance and reconnaissance; and much more,” he said.

The NATO operation over Libya shows an even greater lack of resources and will, Gates said. Operation Unified Protector, he noted, is a sea-air campaign essentially in Europe’s backyard. The mission has widespread political support, doesn’t require ground troops under fire and is vital to Europe’s national interests, he added.

The mission set out by the United Nations has succeeded, Gates said, grounding Moammar Gadhafi’s air force and degrading his regime’s ability to kill his own people.

“While the operation has exposed some shortcomings caused by underfunding,” the secretary said, “it has also showed the potential of NATO, with an operation where Europeans are taking the lead with American support.

“However, while every alliance member voted for the Libya mission, less than half have participated, and fewer than a third have been willing to participate in the strike mission,” he continued. “Frankly, many of those allies sitting on the sidelines do so not because they do not want to participate, but simply because they can’t. The military capabilities simply aren’t there.”

Allies do not have intelligence, surveillance, and reconnaissance assets that would allow more allies to be involved and make an impact, Gates said. To run the air campaign, the NATO air operations center in Italy required a major augmentation of targeting specialists, mainly from the United States, to do the job – a “just in time” infusion of personnel that may not always be available in future contingencies, the secretary said.

“We have the spectacle of an air operations center designed to handle more than 300 sorties a day struggling to launch about 150,” he said. “Furthermore, 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.”

Part of this predicament stems from a lack of will, much of it from a lack of resources in an era of austerity, Gates said. For all but a handful of allies, defense budgets – in absolute terms, as a share of economic output – have been chronically starved for adequate funding for a long time, with the shortfalls compounding on themselves each year, he added.

Despite the demands of mission in Afghanistan — NATO’s first “hot” ground war — total European defense spending has declined by nearly 15 percent over the last 10 years, the secretary said. Furthermore, he added, rising personnel costs, combined with the demands of training and equipping for Afghan deployments, has consumed an ever-growing share of already meager defense budgets.

This means modernization and improving capabilities are being squeezed out, as the world sees today over Libya, he said.

“I am the latest in a string of U.S. defense secretaries who have urged allies privately and publicly, often with exasperation, to meet agreed-upon NATO benchmarks for defense spending,” Gates said. “However, fiscal, political and demographic realities make this unlikely to happen any time soon, as even military stalwarts like the [United Kingdom] have been forced to ratchet back with major cuts to force structure.”

Today, just five of the 28 NATO allies – the United States, the United Kingdom, France, Greece and Albania – exceed the agreed-upon 2 percent of gross domestic product spending on defense. And that probably won’t change, Gates said.

“The relevant challenge for us today, therefore, is no longer the total level of defense spending by allies, but how these limited – and dwindling – resources are allocated, and for what priorities,” he said. “For example, though some smaller NATO members have modestly sized and funded militaries that do not meet the 2 percent threshold, several of these allies have managed to punch well above their weight because of the way they use the resources they have.”

For example, he said, Norway and Denmark have provided 12 percent of allied strike aircraft in the Libya operation, yet have struck about one-third of the targets, and Belgium and Canada also are making major contributions to the strike mission.

“These countries have, with their constrained resources, found ways to do the training, buy the equipment and field the platforms necessary to make a credible military contribution,” Gates said.

But they are the exceptions, he added, as too many allies have been unwilling to fundamentally change how they set priorities and allocate resources.

“The non-U.S. NATO members collectively spend more than 300 billion U.S. dollars on defense annually, which, if allocated wisely and strategically, could buy a significant amount of usable military capability,” Gates said. “Instead, the results are significantly less than the sum of the parts.”

This, he added, not only has shortchanged current operations, but also bodes ill for ensuring NATO has the key common alliance capabilities of the future. Member states, he added, must look at new ways to boost combat capabilities.

“While it is clear NATO members should do more to pool military assets, such ‘Smart Defense’ initiatives are not a panacea,” he said. “In the final analysis, there is no substitute for nations providing the resources necessary to have the military capability the alliance needs when faced with a security challenge. Ultimately, nations must be responsible for their fair share of the common defense.”

All this must be seen in the context of the political world in which NATO operates, Gates said.

“As you all know, America’s serious fiscal situation is now putting pressure on our defense budget, and we are in a process of assessing where the U.S. can or cannot accept more risk as a result of reducing the size of our military,” the secretary said. “Tough choices lie ahead affecting every part of our government, and during such times, scrutiny inevitably falls on the cost of overseas commitments – from foreign assistance to military basing, support and guarantees.”

Gates said he and Obama believe it would be a grave mistake for the United States to withdraw from its global responsibilities, noting that he discussed expanding U.S. engagements in Asia last week at a regional security conference in Singapore.

“With respect to Europe, for the better part of six decades there has been relatively little doubt or debate in the United States about the value and necessity of the transatlantic alliance,” Gates said. “The benefits of a Europe [that is] whole, prosperous and free after being twice devastated by wars requiring American intervention was self-evident.”

For most of the Cold War, U.S. governments of both parties justified defense investments and costly forward bases that made up roughly 50 percent of all NATO military spending, the secretary said. “But some two decades after the collapse of the Berlin Wall, the U.S. share of NATO defense spending has risen to more than 75 percent – at a time when politically painful budget and benefit cuts are being considered at home,” he said.

“The blunt reality,” he continued, “is that there will be dwindling appetite and patience in the U.S. Congress – and in the American body politic writ large – to expend increasingly precious funds on behalf of nations that are apparently unwilling to devote the necessary resources or make the necessary changes to be serious and capable partners in their own defense — nations apparently willing and eager for American taxpayers to assume the growing security burden left by reductions in European defense budgets.”

But NATO can recover, Gates said.

“The members of NATO – individually, and collectively – have it well within their means to halt and reverse these trends, and instead produce a very different future,” he told the assembly. Governments need to take serious steps to protect defense budgets from being further gutted in the next round of austerity measures, he said, and they need to allocate and coordinate the resources they have and follow through on commitments to the alliance and one another.

“It is not too late for Europe to get its defense institutions and security relationships on track,” Gates said. “But it will take leadership from political leaders and policy makers on this continent. It cannot be coaxed, demanded or imposed from across the Atlantic.

“Over the life of the transatlantic alliance, there has been no shortage of squabbles and setbacks,” he continued. “But through it all, we managed to get the big things right over time. We came together to make the tough decisions in the face of dissension at home and threats abroad. And I take heart in the knowledge that we can do so again.”

The secretary’s speech was the last event on a trip that took him to Singapore, Afghanistan and the NATO meeting — his last foreign trip before his June 30 retirement.