Stephen Biddle summarizes in one paragraph the point I've been trying to make on the Iraq War since late 2003:
If the surge is unacceptable, the better option is to cut our losses and withdraw altogether. In fact, the substantive case for either extreme -- surge or outright withdrawal -- is stronger than for any policy between. The surge is a long-shot gamble. But middle-ground options leave us with the worst of both worlds: continuing casualties but even less chance of stability in exchange. Moderation and centrism are normally the right instincts in American politics, and many lawmakers in both parties desperately want to find a workable middle ground on Iraq. But while the politics are right, the military logic is not.
The United States should either pony up significant amount of blood and treasure that it will take to fix the Bush administration's broken endeavor in Iraq or it should go home. Half measures, including phased withdrawals or "strategic redeployments," will only waste resources and perpetuate an issue that has led to sharp divisions on foreign policy. End of story.
The situation in Iraq highlights another Joseph Nye's paradoxical element of American power, something I like to call the impatient enormity factor. Americans are willing to make enormous sacrifices and take on a significant amount of risk on foreign policies. In return for their sacrifice, however, they expect rapid results to match the scope of that sacrifice. Correct me if I'm wrong, but I think it was George C. Marshall who said that the U.S. public wouldn't abide more than five years of fighting against Germany and Japan. This contrasts significantly with the degree that we celebrate U.S. involvement in World War II as popular and even noble ('greatest generation' anyone?).
Contrast this with the United States' response to the Cold War. Rather than contest Soviet power directly, we picked the relatively low-cost, low-risk route of basing U.S. troops in friendly nations, funding proxy wars and backing tinpot dictators. Sure, we funded an expensive reconstruction programs in post-WWII Europe, but it only lasted four years. The only deviation from this pattern was in Vietnam, but like Iraq, we went in thinking the endeavor was going to be relatively easy and come at a low cost.
We get ensnared in the impatient enormity problem when promise of an easy, low-cost effort does not pan out. The administration of the sitting president takes it as an affront to his re-election prospects and/or legacy. I think we can guess how these scenarios end -- the word 'badly' comes to mind. But that is not the only problem with impatient enormity.
The flip-side of the costly overcommitment is the marginal mission creep. This is a scenario where a low-cost policy (frequently sanctions) is applied to a briefly fashionable cause (Burma, Cuba, Libya, Sudan, Venezuela, etc.). Once the policy is put in place and the now-sated populace and the media loose interest, control over it is ceded to one of three groups: (1) members of Congress on the far left or far right (the activists), (2) members of Congress with a vested in the policy outcome (the lobbied), or (3) fanatical mid-level political appointees (assistant secretary and below).
These groups tend to come into office bent on expanding the current set of policies, but not always. I may complain about the Bush administration's efforts to slowly dismantle the arms control institutions of the Cold War more often, but it is no worse than our mindless sanctions against Cuba and Burma.
But hey, I hear that superpowers don't do windows, so I'm probably just illustrating a useless point.