Is it 1966 in Washington?

As the president contemplates his choices regarding Afghanistan—when his incontinent campaigning about health care allows him time to think about anything else—he should study an episode from when he was 4 years old. It is rich in relevance.

In February 1966, a rancorous national argument about the deepening U.S. involvement in Vietnam had reached a rolling boil. A Democratic president was determined to enlarge benevolent government, as he understood it, more than any president since FDR, and more than any president would try to do for another 43 years. Just six months earlier—July 30, 1965—Lyndon Johnson, for whom expanding government provision of health care was a higher priority than any president would make it until 2009, had signed Medicare into law. LBJ was, however, acutely aware that his domestic agenda, about which he cared much more than he did about foreign policy, could be derailed by Vietnam—its costs and its potential for fracturing his party.

In February 1966 there were about 200,000 U.S. troops in Vietnam—the number would peak at 537,000 in 1968—and the Senate Foreign Relations Committee invited the distinguished diplomat and historian George F. Kennan to testify about the war. He said:

"There is more respect to be won in the opinion of this world by a resolute and courageous liquidation of unsound positions than by the most stubborn pursuit of extravagant or unpromising objectives … Our country should not be asked, and should not ask of itself, to shoulder the main burden of determining the political realities in any other country, and particularly not in one remote from our shores, from our culture and from the experience of our people. This is not only not our business, but I don't think we can do it successfully."

Now, there was some woolly flapdoodle. Winning the "respect" of world "opinion" often is not worth much, as Barack Obama is learning. The "world" adores him, and ignores him (about pressure on Iran, about persuading India and China to reduce their economic growth in order to reduce carbon emissions, etc.). And losing a war, which is how "liquidation" of the deep engagement in Vietnam would have been seen by the world, is always costly, especially for a great power.

Nevertheless, Kennan might have been right. More than 55,000 of the eventual 58,220 American deaths in Vietnam came after he testified. The cost of continuing there was disproportionate to any good achieved. The communist conquest of South Vietnam did not affect the Cold War's outcome.

Recently, Adm. Mike Mullen, the highly regarded chairman of the Joint Chiefs of Staff, had what some in the Obama administration probably considered a Shinseki moment. On Feb. 25, 2003, a month before the invasion of Iraq, Gen. Eric Shinseki, then the Army's highest-ranking soldier, was asked during Senate testimony how many U.S. troops would be needed to secure Iraq. "Several hundred thousand," he said. Donald Rumsfeld called that estimate "far off the mark." Events proved otherwise. Recently Mullen told a Senate committee that Afghanistan "probably needs more forces."

Obama now says he ordered 21,000 more troops to Afghanistan to "secure the election." But 6,000 of the 21,000 did not get there until after the election, which was riddled with fraud. If more than five points of President Hamid Karzai's 54.6 percent of the vote was fraudulent, there must be a runoff. Afghanistan's ferocious winter might delay that until April, which would mean six months with even worse governance than usual.

It took six years to stand up an Iraqi Army of 250,000, and still U.S. forces are needed. One (flimsy) reason for persisting in Afghanistan is that it would be good if the country under a Democratic administration were to win a war. (Kosovo hardly counts.) That has not happened since 1945. But a Washington Post–ABC poll shows that only 33 percent of Democrats think we "must win" in Afghanistan. Sixty-six percent of Republicans do, but most Republicans—57 percent—say U.S. forces should be decreased or remain about the same.

U.S. forces might not retreat from Afghanistan, but they are retreating in that country. They are withdrawing from sparsely populated areas to concentrate on population centers, and areas controlled by the Taliban are expanding. There is precedent for a "resolute and courageous liquidation" of an untenable position: After a 1983 terrorist attack killed 241 Americans improvidently based at Beirut airport, Ronald Reagan quickly ended that intervention.