One way to get past the magnificent charm, celebrated windiness, and political staying power of Senator Biden is through the lens of America’s war with Slobodan Milosevic, whom the gentleman from Delaware famously looked in the eye and accused of being a war criminal. Senator Obama’s choice for vice president turns out to be the archetype of what might be called the Kosovo Democrats. They are liberals who, during the 1990s, began to understand the necessity of the unilateral use of American force, even in the face of disapprobation at the United Nations, but changed their minds when the president defying the United Nations was a Republican and, in the war they initially supported, the going got tough.