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...