Quite a romantic analogy, but I think Powell is simply parroting Bush's speech to the Air Force Academy.

The war in Iraq is more analogous to the Spanish-American war, with the sinking of the USS Maine and the propaganda provided by Hurst ("You supply the pictures, I'll supply the war."), or the Vietnam War, with President Johnson's propaganda surrounding the attack on the Maddox.

The similarity being motivating the American people to back a war using false information.