the surge in history:
Military escalation was also LBJ's answer to unrelenting attacks by the Viet Cong and the North Vietnamese in an uncontrollable civil war -- an increase from 16,800 advisers in 1963 to 545,000 combat troops by 1968. But compare that with Bush's increase of about 28,000 U.S. troops in Iraq. If more than half a million troops couldn't succeed in Vietnam, is a total U.S. force of more than 160,000 likely to pacify Iraq? And what can be done when one escalation doesn't do the trick? The more you double down, Johnson and Nixon found, the harder it is to cut your losses.
(...) [the chronology of withdrawal] We do know that despite Nixon's and Kissinger's behind-the-scenes pragmatism, they continued the fighting for four bloody years -- punctuated by their Cambodian "incursion" in the spring of 1970, a U.S.-backed South Vietnamese offensive in Laos in 1971 and the Christmas bombing of North Vietnam in 1972. Throughout, they knew that victory was impossible but hoped that military pressure on Hanoi would force the North Vietnamese into what Nixon called "peace with honor" -- a deal that could end the United States' commitment while preserving its international credibility.
(...) Bush's political concerns are far less personal. He wants a Republican successor, but he faces no direct electoral retribution. No matter what happens in Iraq, his presidency will end in January 2009. That frees him up considerably to stay the course -- despite the unease that doing so is creating among the GOP's presidential candidates and among congressional Republicans who fear that Iraq will cost them the chance to win back the Hill.