How do you know when you are right? I wonder if the answer is the same as to the question: How do you know when those you disagree with are wrong?
Actually, it's quite complicated. It can be pretty hard to tell when a particular policy was the wrong one without knowing what other policies were realistically available. About the most we can say is that a policy is wrong when it fails to achieve its objectives, which doesn't say very much about what a better policy would have been.
Let me give an illustrative example from a recent, influential essay in Foreign Policy. Stephen Walt, a professor at Harvard and a noted realist, is not a writer generally afflicted with self-doubt. "Would the United States and the world be better off today if the last three presidents had followed the dictates of realism? The answer is yes."
First, according to this argument, the United States would not have invaded Iraq in 2003 but would have concentrated on eliminating al Qaeda. Thousands of soldiers and civilians would still be alive; Iran would have less influence; the Islamic State would not exist. Second, the United States would not have expanded NATO, committing us to defend the Baltics, attracting a Ukrainian bid for membership and prompting a negative Russian reaction. Crimea would still be a part of Ukraine and the fighting in eastern Ukraine probably would not have occurred. Third, the United States would have never adopted a strategy of "dual containment" with respect to Iran and Iraq that forced Washington to open bases in Saudi Arabia, provoking Osama bin Laden's wrath. "A realist approach to Persian Gulf politics would have made [the 9/11] attack less likely, though of course not impossible." Had President Barack Obama listened to the realists, the United States would not have joined the coalition that removed Moammar Gadhafi from power in Libya, creating yet another failed state. "One might question some of these claims, but on the whole realists have a much better track record than those who keep insisting the United States has the right, responsibility, and wisdom to manage virtually every important global issue, and who have repeatedly urged Washington to take actions that now look foolish."
Assuming these claims to be true, they do not show that realists have a much better "track record" because, as Walt laments, they weren't in the race. We don't know exactly how the world would look if Saddam Hussein were still in power in Iraq, accumulating vast resources without the irritating need to circumvent sanctions, unchastened by a coalition that simply accepted his refusal to carry out the terms of the cease-fire agreement that saved his regime in 1991. We don't know the extent to which extending NATO membership to the Baltics has kept them safe — after all, Russian President Vladimir Putin did not annex Latvia. We don't know what pretext he would've used to seize Crimea, regardless of events in Kiev. It strikes me as highly implausible that 9/11 could've been avoided had the United States determined not to put bases in Saudi Arabia, however much that may have annoyed bin Laden. And while it may be true that the West has proved itself inept at managing a post-Gadhafi Libya, it hardly follows that the Gadhafi regime would be in power today in a peaceful Libya had the United States not joined Britain and France in providing air cover for Benghazi. Indeed, in Syria the Obama administration has, if only by happenstance, refused to use its forces to remove the dictator and Syria is no less a failed state for it.
What we do know has been pithily expressed by Tony Blair: "We've tried intervention and putting down troops in Iraq. We've tried intervention without putting in troops in Libya. And we've tried no intervention at all but demanding regime change in Syria." When we acted in Iraq, we failed; when we sort of acted in Libya, we failed; when we refused to act in Syria, we failed. What exactly does that "failure" consist of (regardless of whether a realist policy would have succeeded)?
When we acted in Iraq, we failed; when we sort of acted in Libya, we failed; when we refused to act in Syria, we failed.
Take Iraq and our ill-starred intervention there. Failure occurs when the aim of the policy is not achieved at an acceptable cost. If we have failed in Iraq, it is not because the coalition failed to remove a very serious contender for nuclear proliferation (without which, by the way, an agreement with Iran on limiting its nuclear capacity would never have been possible). It's rather because the costs to the United States and especially to the Iraqi people are still mounting. We don't know whether a 400,000-person force composed of constabularies from the region and a reconstituted Iraqi police could've stabilized the situation in 2003, although we can say that the usual realist answer that a larger invasion force was needed misses the point. But what we can say is that it was a failure to appreciate the changing nature of warfare that robbed us, and the Iraqi people, of the victory for which they and we have suffered so much.
This is especially important now as more and more people are coming to the conclusion that we are and have been for some time in a war on terror. Perhaps the most formidable obstacle to appreciating that state of affairs has been the apparent absurdity of an armed conflict with a technique — global terrorism — or even more absurdly, with an emotion: terror. How could we possibly achieve a victory over terror? Who would sign the surrender agreement?
And yet if we appreciate the humbling limitations of analysis I've been describing, we might nevertheless be able to answer this conundrum. Most people think of victory as the defeat of the enemy. That is victory in football, or if you prefer, chess. Victory in warfare is the achievement of the war aim at an acceptable cost.
The war aim in a war on terror is the protection of civilians. It doesn't have a punctuating finality, but must be re-achieved every morning. But at long last surely we can appreciate that victory is not simply the destruction of enemy soldiers and populations; we did enough of that in Vietnam and still lost the war.
What we are facing is a novel problem in the history of warfare, and until we learn to cope with it successfully we will have to endure the after-action advice that it all really would've turned out better if we simply hadn't gotten involved. That is not the lesson of Syria, for unlike other conjectural analyses, it is hard to imagine it turning out worse.