I've been thinking this week about U.S. defense spending and grand strategy. It's increasingly clear that while the sequester may be an accounting and planning nightmare for Pentagon officials, it's not going to leave the United States naked and defenseless before its enemies. How could it? Even after the 9 percent budget cut mandated by the sequester, the United States is still going to spend at least four times more than the number two military power (China). Moreover, the United States is in a remarkably favorable geopolitical position -- with friendly countries on both borders and no great power rivals nearby -- and it has thousands of nuclear weapons to deter attack. As I've noted before, this remarkably high level of basic territorial security is why foreign policy mavens in the United States can devote their time to worrying about and meddling in far-flung backwaters.

Nonetheless, a reduced defense budget is bound to have some effects. How should Americans think about it? Here are three quick ideas.

First, one wrong way to respond is to engage in threat inflation. This was the Pentagon's reflexive answer as the sequester approached. Top military leaders began shouting that the sky was about to fall and that sequestration was going to turn the United States, as former SecDef Leon Panetta put it, into "a second rate power." The commandant of the Marine Corps, James Amos, said the sequester would have a "devastating impact" on military readiness and create "unacceptable levels of risk." The chairman of the Joint Chiefs, Martin Dempsey, told Congress a year ago that "in my personal military judgment, formed over 38 years, we are living in the most dangerous time in my lifetime, right now."  

In a rare moment of sanity, Congress didn't fall for these scare tactics. And my guess is that this sort of alarmism won't work well in the future either, because Al Qaeda is on the ropes, China isn't a peer competitor yet, and even a healthier U.S. economy is going to face fiscal pressures -- an aging population, deferred maintenance on U.S. infrastructure, etc. -- that will be hard for the Pentagon to tilt against.  

Second, an equally bad response would be to assume the U.S. military can and should try to perform every one of its current missions as its capabilities decline. Not only is that unfair to the men and women in uniform, it's also bad strategy. Even if you believe that we've been spending more than we needed to in recent years, there ought to be some correspondence between capabilities and commitments. If you spend less and have to trim force structure and other capabilities, the missions you are committed to perform ought to shrink too, which, in turn, means rethinking how the U.S. uses its power around the world and being more selective in identifying and setting priorities.

Third, the right way to think about this issue is to focus more attention on interests -- both our own and those of our allies. For the past fifty years or more, America's overarching power made it possible to expand our definition of "interests" almost without limit. And as the world's most powerful country, we assumed it was our right and responsibility to do most of the heavy lifting in various trouble spots. That tendency increased even more after the Soviet Union collapsed, leaving us without a peer competitor and in a position of (nearly) unchallenged primacy. Our Foreign Policy Mandarins readily embraced this role, as it gave them lots of missions to perform and allowed them to strut around the world telling other countries what to do. U.S. officials began to describe the United States as the "indispensable nation" and assumed that the solution to most (all?) global problems had to be "Made in America."

Today, having been chastened by Iraq, Afghanistan, and the financial crisis and facing the prospect of a serious, long-term competition with China that is in its early stages, it behooves American strategic planners to move from a power-centered perspective to one that focuses more closely on interests. Specifically, when problems arise in particular areas, our first question should not be "what can we do about this?" but rather "who has the greatest interest in this problem?" And if there are other states that share our basic outlook and have a greater interest in the issue, then we should let them take the lead and bear the burden of addressing it, with the United States playing a back-up role when appropriate.

IR theorists have a term for this -- "buck-passing." It may not sound heroic, but it's often a superb strategy. If you can get others to pay the price and bear the burden, then you can often get the results you want at very low cost. And as the United States learned in both world wars, keeping one's powder dry while others rush to war sometimes puts you in an excellent position to win the peace. It is hardly fool-proof, of course, but the good news is that America's remarkably favorable geostrategic position gives us a greater opportunity to pursue this approach at relatively little risk.

One can see the seeds of this new approach in the Obama administration's response to events in Libya, Mali, and Syria. Instead of placing the United States in the vanguard -- which invariably generates concern, resentment, and free-riding -- Washington has let countries with a greater interest in the outcome take the lead. It has not been entirely aloof, of course -- especially in the Libyan case -- but it has kept its commitments appropriately modest. Not only does that keep us out of additional costly quagmires, but it also keeps us from pouring gasoline on conflicts that might in fact get worse if we do. Far from being a sign of strategic impotence, one might think of it instead as a sign of good judgment.

This is not isolationism. Instead, think of it as "playing hard to get." American power is still enormous and a great asset for others, which means they should be willing to go a long way to accommodate us in order to be able to obtain it. The only way to get others -- including our allies -- to do more to address common security problems is for the United States to do less, especially in those areas where others have a greater stake in the issue than we do. If Uncle Sucker insists on doing it all, others will be happy to let us while they stand around carping about heavy-handed American interference.  

The challenge going forward lies in striking the right balance between engagement and independence -- doing just enough so that others know they can count on us if needed but not so much that those with a greater stake take advantage of our overweening ambition. By the way, that will be primarily a task of intelligence and diplomacy, not military strategy. And while the sequester is a pretty stupid way to trim defense spending (i.e., Panetta was right to call it a "goofy meataxe"), it might have a silver lining. If it accelerates the process of rethinking our overall grand strategy, then the net effect might be quite salutary.

If you were focusing on Hurricane Isaac or the continued violence in Syria, you might have missed the latest round of threat inflation about China. Last week, the New York Times reported that China was "increasing its existing ability to deliver nuclear warheads to the United States and to overwhelm missile defense systems."  The online journal Salon offered an even more breathless appraisal: the headline announced a "big story"--that "China's missiles could thwart U.S."--and the text offered the alarming forecast that "the United States may be falling behind China when it comes to weapon technology."

What is really going on here?  Not much.  China presently has a modest strategic nuclear force.  It is believed to have only about 240 nuclear warheads, and only a handful of its ballistic missiles can presently reach the United States.  By way of comparison, the United States has over 2000 operational nuclear warheads deployed on ICBMs, SLBMs, and cruise missiles, all of them capable of reaching China.  And if that were not enough, the U.S. has nearly 3000 nuclear warheads in reserve.

Given its modest capabilities, China is understandably worried by U.S. missile defense efforts.  Why?  Chinese officials worry about the scenario where the United States uses its larger and much more sophisticated nuclear arsenal to launch a first strike, and then relies on ballistic missile defenses to deal with whatever small and ragged second-strike the Chinese managed to muster.  (Missile defenses can't handle large or sophisticated attacks, but in theory they might be able to deal with a small and poorly coordinated reply).

This discussion is all pretty Strangelovian, of course, but nuclear strategists get paid to think about all sorts of elaborate and far-fetched scenarios.  In sum, those fiendish Chinese are doing precisely what any sensible power would do: they are trying to preserve their own second-strike deterrent by modernizing their force, to include the development of multiple-warhead missiles that would be able to overcome any defenses the United States might choose to build.  As the Wall Street Journal put it:

The [Chinese] goal is to ensure a secure second-strike capability that could survive in the worst of worst-case conflict scenarios, whereby an opponent would not be able to eliminate China's nuclear capability by launching a first strike and would therefore face potential retaliation. As the U.S. Defense Department's Ballistic Missile Defense Review points out, "China is one of the countries most vocal about U.S. ballistic missile defenses and their strategic implications, and its leaders have expressed concern that such defenses might negate China's strategic deterrent."

Three further points should be kept in mind. First, hawks are likely to use developments such as these to portray China as a rising revisionist threat, but such claims do not follow logically from the evidence presented. To repeat: what China is doing is a sensible defensive move, motivated by the same concerns for deterrent stability that led the United States to create a "strategic triad" back in the 1950s.  

Second, if you wanted to cap or slow Chinese nuclear modernization, the smart way to do it would be to abandon the futile pursuit of strategic missile defenses and bring China into the same negotiating framework that capped and eventually reduced the U.S. and Russian arsenals. And remember: once nuclear-armed states have secure second-strike capabilities, the relative size of their respective arsenals is irrelevant. If neither side can prevent the other from retaliating and destroying its major population centers, it simply doesn't matter if one side has twice as many warheads before the war. Or ten times as many. Or a hundred times....

Third, this episode reminds us that trying to protect the country by building missile defenses is a fool's errand. It is always going to be cheaper for opponents to come up with ways to override a missile defense. Why? Because given how destructive nuclear weapons are, a missile defense system has to work almost perfectly in order to prevent massive damage. If you fired a hundred warheads and 95% were intercepted -- an astonishingly high level of performance -- that would still let five warheads through and that means losing five cities.  And if an opponent were convinced that your defenses would work perfectly -- a highly unlikely proposition -- there are plenty of other ways to deliver a nuclear weapon. Ballistic missile defense never made much sense either strategically or economically, except as a make-work program for the aerospace industry and an enduring component of right-wing nuclear theology.