At a midtown bar, Wolcott Wheeler, whom I call a historian without portfolio, tells me a story about Robert Oppenheimer: how the physicist, meeting President Harry Truman in the Oval Office, said, "Mr. President, I have blood on my hands."

The episode is a famous one, and I know it. But Wolly goes on.

In response, Truman took a handkerchief out of his pocket and, offering it to him, said, "Would you like to wipe them?" After the scientist left, Truman turned to Dean Acheson and said, "Blood on his hands! Dammit, he hasn't half as much blood on his hands as I have! You just don't go around bellyaching about it."