Here's a strategic puzzle for you: How do you convince the American people to support the kind of wars we seem to be fighting these days, especially when these "wars of choice" aren't about defending U.S. territory or vital overseas interests?
Way back when, the American people enthusiastically backed American entry into World War I (in 1917) and World War II (in 1941). Public opinion had been deeply divided until shortly before the decision to intervene, but in each case Americans eventually recognized a threat to vital interests and from then on supported the raising of vast armies without much complaint.
Similarly, there was a strong bipartisan consensus behind the Cold War strategy of containment, and even debacles such as Vietnam did not erode the U.S. commitment to Europe and its other Asian allies. As realists like Kenneth Waltz and Hans Morgenthau realized, Vietnam (and other interventions in the developing world) were mostly a costly diversion from the main Cold War competition.
Today, however, the United States doesn't face the sort of imminent threat that Wilhelmine and Nazi Germany, Imperial Japan, or Soviet Russia once posed. China may be a genuine peer competitor someday, but it has a long way to go. The threats we face come from various minor powers -- Serbia, Iraq, Ghaddafi's Libya, North Korea, etc. -- who are occasionally annoying and sometimes say or do objectionable things, but aren't in any position to attack the American homeland directly or threaten the independence of important U.S. allies.
I'd include Iran in that category too, despite all the hype about its nuclear program and its support for groups like Hezbollah. Iran remains a minor military power with very limited capabilities, and groups like Hezbollah are not an existential threat to anyone. By contrast, it should be clear by now that the United States is an existential threat to governments it doesn't like, as Milosevic, Ghaddafi, Noriega, and Saddam Hussein all discovered. And who knows? Maybe Assad will be next to learn this lesson. Whatever its intentions might be, Iran's ability to threaten its neighbors is paltry by comparison.
Add to this the fact that today's strategic challenges mostly arise from within deeply troubled societies that are torn by internal divisions. Sometimes the problem is that no one is in charge (Somalia, Yemen, Afghanistan, etc.); sometimes the problem is a dictator who is keeping the lid on by ruling with an iron hand. Trying to fix these places cannot be done easily or overnight, which means that anyone who intervenes has got to be prepared to stick around a long time in order to have much hope for success.
But who wants to make a long-term, and therefore costly, commitment when there aren't real vital interests involved? That's our strategic problem in a nutshell: it's easy to get Americans to make sacrifices when there really is a large and hungry wolf at the door, but it's hard to get them to spend hundreds of billions on places that don't really matter that much. Which is mostly where we've been fighting lately.
So if there aren't any looming geopolitical threats, how do you get the United States to take military action? One obvious tactic is threat-inflation: you treat modest military challenges of the sort just described as if they were the reincarnation of Stalin's Russia or the Third Reich. It helps if some of these leaders are loudmouthed clowns like Mahmoud Ahmadinejad, and if you can count on self-interested allies to make your case for you. That's basically what happened with Iraq, and advocates of war with Iran are operating from the same playbook. Fortunately, thus far the hard sell isn't working.
Next, you can also engage in task-deflation, meaning that you claim that dealing with these various troublemakers can be done cheaply and quickly. Clinton told us in 1996 we'd be in the Balkans for only 12 months; he was off by about nine years. In 2002, SecDef Donald Rumsfeld correctly forecast that a small U.S. force could topple the Taliban, but he failed to realize that creating a stable Afghanistan would take a much larger foreign presence, require more than a decade, and was still likely to fail. The neoconservative geniuses who dreamt up the Iraq War also promised victory would be swift, pay for itself, and would quickly transform the Middle East into a sea of pro-American democracies. Wrong on all counts, alas. Yet even Barack Obama succumbed to this tendency, arguing that a short-term "surge" in Afghanistan would turn the tide and produce a far better outcome in the long run. Doesn't seem to be the case.
In the annals of post-Cold War military intervention, the Panamas and Libyas (maybe) are the exception. Instead of swift and cheap victories, we tend to get long and protracted commitments over relatively minor interests. And once that happens, public support evaporates and you're forced to leave without finishing the job.
Finally, as the New York Times' David Sanger has argued, presidents can try to keep these wars going by engaging in concealment. To the extent that you can, keep the fighting off the front page and don't let the taxpayers who are paying for it know what is really going on. Don't tell them very much about night raids, targeted killings, or the full extent of drone warfare, because they might begin to question the long-term efficacy of these tactics and be concerned that their tax dollars are killing a lot of innocent people by mistake. To do this, of course, you have to prosecute anyone who leaks information about these activities, unless they are a top-level official leaking to a tame journalist or former SEAL or other military figure with patriotic credentials. It also helps to have an all-volunteer force, so that the human costs of the war are confined to a narrow sector of society and so most young people (and their families) don't have to bear any of these costs themselves.
Unfortunately, these various machinations are likely to impose a hefty long-term price. The AVF may be economically efficient, but we are increasingly dependent on a narrow warrior caste instead of relying on a broadly mobilized population. And it is a caste that no politician dares criticize, which erodes and weakens civilian control over the military. It is no longer as clear that the AVF is such an economic bargain either, given the long-term benefits that veterans demand and the cushy arrangements that we have to provide them in the field. To say this is not to denigrate our troops' patriotism or the sacrifices they have made; it is simply to say that wars costs a lot more to fight when you are delivering a lot of creature comforts in a landlocked country like Afghanistan.
Similarly, wars that can only be waged via threat-inflation or by concealing what our troops are really doing inevitably corrupts public discourse and distorts public perceptions of America's real role in the world. We constantly ask ourselves "why do they hate us?" and one reason we don't know the answer is that we may not know what is actually being done in our name in some far-flung corner of the world.
Where does this train of logic leave me? If you can't get public support for low-level but long-term military commitments for relatively minor stakes without threat-inflating, task-deflating, or concealing what you're up to, maybe you shouldn't be doing these things in the first place. Just a thought.
Stephen M. Walt is the Robert and Renée Belfer professor of international relations at Harvard University.