“I am worried,” he said in an Associated Press interview in his Pentagon office on Monday.

Throughout the Cold War, beginning with NATO’s founding in 1949 as a bulwark against the Soviet Union and its East European allies, a military and political partnership with Western Europe was fundamental to U.S. defense policy.

But in the 20 years since the demise of the Soviet Union the security landscape has been reshaped. And for a growing number of Americans, NATO is an obscure relic of a bygone era.

It’s not just the reluctance of most European governments to shoulder a bigger share of the financial burden of providing their own defense that bothers Gates, although he said this is at the core of the problem. What has added to his worry is what Gates sees as an emerging new view among younger Americans of the proper priorities for American foreign and defense policy.

“People like me who have an emotional stake in Europe and NATO are aging out,” he said in the interview. “For a lot of these younger people,” including newer members of Congress bent on cutting government budget deficits and trimming U.S. commitments overseas, “they don’t have these kinds of attachments.”

Gates said he had no regrets about the blunt message he delivered in Brussels, which included an explicit warning that the European members of NATO face the very real possibility of “collective military irrelevance.”

“I don’t feel I went too far,” he said. “I’ll tell you one place I got pretty unanimous positive reaction, and that was in the United States of America — across the entire political spectrum.”

Sean Kay, a professor of politics and government at Ohio Wesleyan University and a specialist in European and international security, said in a telephone interview that the U.S. might get Europe to do more for its own defense if it began withdrawing troops and considered moving U.S. European Command headquarters to U.S. soil.

“A key premise of NATO’s founding was that Europe needed the confidence to get on its feet” after the devastation of World War II — “not that it should be a permanent appendage to American military power,” Kay said.

Even though the threat of a land invasion of Europe is nearly nonexistent, the U.S. still keeps a small number of nuclear weapons in Europe. And the Obama administration is moving ahead with plans for a NATO-wide network of missile interceptors and radars designed to protect all European members from missile attacks by Iran.

Gates, who began a 27-year CIA career in 1966 and has worked for eight presidents, is a firm believer that the U.S. should not relinquish its predominant military role in the world. And he is adamant that maintaining that presence in foreign lands — not just in Europe but also Asia — is a crucial underpinning of that role.

“Make no mistake, the ultimate guarantee against the success of aggressors, dictators and terrorists in the 21st century, as in the 20th, is hard power — the size, strength and global reach of the United States military,” he said in a commencement address at the University of Notre Dame last month.

And that will not end when the wars in Iraq and Afghanistan are over, he added.

“Our military credibility, commitment and presence are required to sustain alliances, to protect trade routes and energy supplies, and to deter would-be adversaries from making the kind of miscalculations that so often lead to war,” he said.

In the AP interview, Gates said he does not foresee a sudden rupture with Europe or NATO.

“I don’t think it will be as dramatic as a break,” he said. “But it’ll just be slowly growing apart — it’s a troubled marriage.”

Leon Panetta, the CIA director who is Gates’ designated successor, agrees that NATO is not shouldering enough of the defense burden. But in written responses to questions from the Senate Armed Services Committee prior to his confirmation hearing, Panetta was far less explicit about his view of the alliance’s future.

“It is my sense that a number of our NATO allies, while fulfilling their current commitments, have been underperforming in terms of their own investments in defense capabilities,” especially in deployable combat forces, he wrote.

He added that the U.S. has “enormous stakes in a strong, mutually supportive NATO alliance.”

“Future U.S. political leaders – those for whom the Cold War was not the formative experience that it was for me – may not consider the return on America’s investment in NATO worth the cost,” he told a European think tank on the final day of an 11-day overseas journey.

Gates has made no secret of his frustration with NATO bureaucracy and the huge restrictions many European governments placed on their military participation in the Afghanistan war. He ruffled NATO feathers early in his tenure with a direct challenge to contribute more front-line troops that yielded few contributions.

Even so, Gates’ assessment Friday that NATO is falling down on its obligations and foisting too much of the hard work on the U.S. was unusually harsh and unvarnished. He said both of NATO’s main military operations now — Afghanistan and Libya — point up weaknesses and failures within the alliance.

“The blunt reality 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,” he said.

Without naming names, he blasted allies who are “willing and eager for American taxpayers to assume the growing security burden left by reductions in European defense budgets.”

The U.S. has tens of thousands of troops based in Europe, not to stand guard against invasion but to train with European forces and promote what for decades has been lacking: the ability of the Europeans to go to war alongside the U.S. in a coherent way.

The war in Afghanistan, which is being conducted under NATO auspices, is a prime example of U.S. frustration at European inability to provide the required resources.

“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,” Gates said.

Gates, a career CIA officer who rose to become the spy agency’s director from 1991 to 1993, is retiring on June 30 after 4 1/2 years as Pentagon chief. His designated successor, Leon Panetta, is expected to take over July 1.

For many Americans, NATO is a vague concept tied to a bygone era, a time when the world feared a Soviet land invasion of Europe that could have escalated to nuclear war. But with the demise of the Soviet Union in 1991, NATO’s reason for being came into question. It has remained intact — and even expanded from 16 members at the conclusion of the Cold War to 28 today.

But reluctance of some European nations to expand defense budgets and take on direct combat has created what amounts to a two-tier alliance: the U.S. military at one level and the rest of NATO on a lower, almost irrelevant plane.

Gates said this could spell the demise of NATO.

“What I’ve sketched out is the real possibility for a dim, if not dismal future for the trans-Atlantic alliance,” he said. “Such a future is possible, but not inevitable. The good news is that 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.”

Gates has said he believes NATO will endure despite its flaws and failings. But his remarks Friday point to a degree of American impatience with traditional and newer European allies that in coming years could lead to a reordering of U.S. defense priorities in favor of Asia and the Pacific, where the rise of China is becoming a predominant concern.

To illustrate his concerns about Europe’s lack of appetite for defense, Gates noted the difficulty NATO has encountered in carrying out an air campaign in Libya.

“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 said.

His comment reflected U.S. frustration with the allies’ limited defense budgets.

“To avoid the very real possibility of collective military irrelevance, member nations must examine new approaches to boosting combat capabilities,” he said.

He applauded Norway and Denmark for providing a disproportionate share of the combat power in the Libya operation, given the size of their militaries. And he credited Belgium and Canada for making “major contributions” to the effort to degrade the military strength of Libya’s Moammar Gadhafi.

“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,” he said.

But they are exceptions, in Gates’ view.

A NATO air operations center designed to handle more than 300 flights a day is struggling to launch about 150 a day against Libya, Gates said.

On a political level, the problem of alliance purpose in Libya is even more troubling, he said.

“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 said. “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.”

Afghanistan is another example of NATO falling short despite a determined effort, Gates said.

He recalled the history of NATO’s involvement in the Afghan war — and the mistaken impression some allied governments held of what it would require of them.

“I suspect many allies assumed that the mission would be primarily peacekeeping, reconstruction and development assistance – more akin to the Balkans,” he said, referring to NATO peacekeeping efforts there since the late 1990s. “Instead, NATO found itself in a tough fight against a determined and resurgent Taliban returning in force from its sanctuaries in Pakistan.”

He also offered praise and sympathy, noting that more than 850 troops from non-U.S. NATO members have died in Afghanistan. For many allied nations these were their first military casualties since World War II.

He seemed to rehearse his position in the coming debate within the Obama administration on how many troops to withdraw from Afghanistan this year.

“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,” he said.

He said the “vast majority” of the 30,000 extra troops Obama sent to Afghanistan last year will remain through the summer fighting season. He was not more specific.

In a question-and-answer session with his audience after the speech, Gates, 67, said his generation’s “emotional and historical attachment” to NATO is “aging out.”

He said he is not sure what this means in practical terms. But if Europeans want to keep a security link to the U.S. in the future, he said, “the drift of the past 20 years can’t continue.”

——

Robert Burns can be reached at http://twitter.com/robertburnsAP

The Obama administration has not yet released details of the planned reduction in its troop numbers in Afghanistan.

THIS IS A BREAKING NEWS UPDATE. Check back soon for further information. AP’s earlier story is below.

BRUSSELS (AP) — NATO’s chief says he is confident U.S. troop withdrawals from Afghanistan due to start in July will not affect security in the war-torn country.

Alliance Secretary-General Anders Fogh Rasmussen was speaking after Germany urged the United States on Thursday not to pull too many troops out of Afghanistan next month, saying a major reduction in American forces could risk NATO’s strategy in the 10-year conflict.

He also said there would be no “rush for the exits” by other NATO allies fighting in Afghanistan when America begins cutting its 100,000-strong force there.

The Obama administration has not yet released details of the planned reduction in its troop numbers in Afghanistan.

“We are willing to have a presence beyond (2011), but we’ve got a lot of commitments,” he said, not only in Afghanistan and Libya but also in Japan, where he said 19 U.S. Navy ships and about 18,000 U.S. military personnel are assisting in earthquake, tsunami and nuclear reactor relief efforts.

“So if folks here are going to want us to have a presence, we’re going to need to get on with it pretty quickly in terms of our planning,” he added. “I think there is interest in having a continuing presence. The politics are such that we’ll just have to wait and see because the initiative ultimately has to come from the Iraqis.”

Army Gen. Lloyd Austin, the top American commander in Iraq, said the country is lacking important security capabilities. Those include the defense of its air space and the wherewithal to supply and maintain its own forces, he said.

Asked in an interview whether all Iraqi government officials are aware of these gaps, he replied, “Some more than others.”

He said the government’s inability thus far to appoint a defense minister and an interior minister has hampered its ability to make informed decisions about whether to ask the Americans to stay longer.

Speaking to a group of reporters traveling with Gates, Austin gave the strong impression that he thinks Iraq needs a U.S. military presence beyond December, but he said he had not yet been asked to provide a recommendation to Washington.

He said Iraq faced the possibility of a “more violent environment” next year, given the absence of U.S. military force and the failure to resolve key political problems, like the Kurd-Arab tensions in Kirkuk and elsewhere in the north.

The U.S. now has about 47,000 troops in Iraq, and they will begin leaving in large numbers in late summer or early fall. The U.S. led an invasion in March 2003 that toppled the government of President Saddam Hussein a month later, but an insurgency soon set in and the U.S. got mired in a conflict that has lasted far longer — and cost far more American and Iraqi lives — than Washington had anticipated.

Gates also said civil unrest in the Persian Gulf kingdom of Bahrain, with majority Shiite Muslims pushing for an end to rule by the minority Sunnis, has created tensions in Iraq, whose Shiite prime minister, Nouri al-Maliki, is concerned about Bahrain’s crackdown on Shiites.

Gates said he expected to discuss this subject with al-Maliki in private meetings later Thursday.

Meghan O’Sullivan, a top Iraq adviser to President George W. Bush from 2005-07, said in an email exchange that al-Maliki faces enormous domestic political pressures on several fronts, including a small but vocal number of Iraqis demanding better government, and a security situation that is improved but still tense.

Together, these pressures make it unlikely that al-Maliki feels he can publicly invite the U.S. military to stay beyond this year.

“Understandably, the Obama administration was hoping for this sort of invitation, and likely feels struck, given that it is not forthcoming,” O’Sullivan said. “They can’t be seen wanting to keep more troops in Iraq than the Iraqis do.” O’Sullivan is now a professor of international affairs at Harvard University’s John F. Kennedy School.

Under blue skies and a bright sun at a U.S. base just outside the Iraqi capital, Gates told a group of soldiers that he worries that a potential shutdown of the U.S. federal government will delay issuance of their paychecks. He assured them that they eventually would get full pay, but there could be a delay if Democrats and Republicans in Washington are unable to reach a budget deal this week.

“When I start to think of the inconvenience that it’s going to cause these kids (soldiers) and a lot of their families, even a half paycheck delayed can be a problem for them,” Gates told reporters after fielding several questions from the assembled soldiers. The first question posed to him was by a soldier asking about the ramifications for military members and their families of the budget crisis back home.

Gates assured them, “You will be paid,” then added that it might take a while, depending on the length of the political impasse in Washington.

In a brief exchange with reporters during a photo session with Gates earlier Thursday, the U.S. ambassador to Baghdad, James Jeffrey, said U.S. ground forces are “the glue” that is holding the country together. He said this leaves a mixed picture of the situation in Iraq because making arrangements to keep U.S. troops here beyond December is going to be difficult.

In his troop talk, Gates raised the matter of his impending retirement, recalling for soldiers of the 2nd Brigade, 1st Infantry Division, that his first visit to Iraq was in September 2006, three months before he replaced Donald H. Rumsfeld as defense secretary. He recalled that on a visit to Baghdad in December 2006 he conducted a press conference while a gun battle was echoing in the distance.

In all, he estimated he has made 14 visits to Iraq.

“‘This will probably be my last one,” he said.

Gates previously has said he intends to retire this year, but he has not been more specific about the timing. It is widely anticipated that he is planning to quit this summer.

What war proponents did not bank on, however, was this latest exercise in “shock and awe” also unmasking unspoken and uncomfortable realities at the twilight of American empire. Here are just a few:

– America Suffers from a Bad Case of Selective Deficit Disorder: Dick Cheney once said “deficits don’t matter,” and that attitude defines our increasingly acute case of Selective Deficit Disorder — i.e., the disease whereby politicians express concern about deficits only when it justifies cutting non-military expenditures. Just weeks ago, both political parties were calling America “broke” and competing to show who was more concerned about reining in spending. Most of these same deficit hawks, though, seem unconcerned about all that cash being spent on million-dollar cruise missiles in North Africa.

– America Doesn’t Really Care About the Constitution: Despite the Tea Party-inspired talk about “enumerated powers” in the Constitution, the Libya invasion shows that few on either the left or right genuinely care about our country’s founding document. We know this because there’s been so little outcry about President Obama invading Libya without a constitutionally mandated congressional declaration of war. The silence is particularly deafening considering Obama himself explicitly said in 2007 that such unsanctioned invasions are blatantly unconstitutional.

– America Has Made Patriotism the Refuge of Partisans: During the Iraq invasion, Republican partisans regularly insinuated that Democratic war opponents were unpatriotic because their criticism allegedly helped Saddam Hussein. We hear the same demagogic argument today with regard to Gadhafi, only now from Obama partisans. Indeed, see for yourself — log onto Twitter or Facebook or a liberal blog, and dare question the premise of the Libya invasion. Inevitably, some of the same Bush opponents who took umbrage at being called Saddam sympathizers will deride you as an unpatriotic Gadhafi lover. By this inanely hyperpartisan logic, of course, anyone opposing an immediate invasion of North Korea is a huge fan of Kim Jong Il.

– American Policymakers Aren’t Motivated by Humanitarian Concerns: Though many Americans unflinchingly accept the Obama administration’s humanitarian rationale for the Libya incursion, the justification is laughable coming from an administration that called Egypt’s American-financed dictator Hosni Mubarak “a friend,” labels the Saudi royal family an ally and this weekend praised Syria’s Bashar al-Assad as “a reformer” even as he now massacres his own people. The Libya War is about a lot of things — oil, defense contracts, the Pentagon’s brand-new Africa Command establishing its first foothold on the resource-rich continent, etc. — but it is not primarily about saving lives.

Secretary of Defense Robert Gates told ABC News this week that Libya poses no imminent threat to America and that its civil war is “not a vital national interest to the United States.” The same cannot be said for the painful truths the conflict underscores. If left unaddressed, they threaten our budget, Constitution and credibility far more than any tyrant or terrorist ever could.