U.S. wars have been strewn with damaging tactical and strategic blunders

As President Obama moves ahead with his expansion of the war in Afghanistan, history suggests that he has a better chance of being wrong than right.

Judging from the experience of Woodrow Wilson, Harry Truman, John Kennedy, Lyndon Johnson, Richard Nixon and George W. Bush, miscalculations about war and peace are all too common. Despite receiving counsel from the best and the brightest in each of their generations, these presidents received poor advice that each should have resisted.

Wilson's Fourteen Points of January 1918, which were an amalgam of high-minded progressive thinking, described a postwar world that was beyond reach: a peace without victors, disarmament, self-determination for nationalities, a world safe for democracy, and an end to war through collective security provided by a league of nations. It was a mirage that did nothing to prevent the rise of Nazism and the onset of another world war.

Truman's miscalculation followed a series of wise steps between 1945 and 1950 in the emerging Cold War. The fact that realistic good sense — containment as played out in the Truman Doctrine and the Marshall Plan — characterized his initial Cold War decisions was no assurance that he would get things right in the Korean conflict. His decision to beat back North Korea's attack on South Korea in June 1950 now enjoys almost universal approval as a sensible extension of the containment response to communist aggression.

Yet the decision to cross the 38th parallel in order to unify Korea under a representative government was a blunder that cost the United States, Koreans and Chinese considerable blood and treasure. Gen. Douglas MacArthur's advice that the Chinese would not enter the fighting if we crossed the parallel and that they would suffer a great defeat if they did, with American troops returning home in a matter of weeks, was the greatest miscalculation of his military career. Moreover, it destroyed Truman's presidency: Unable to end the war or put across the domestic reforms promised in his 1948 election campaign, his approval rating fell to 23%.