No one is as familiar with the frustrations of building missile defenses as Secretary of Defense Donald Rumsfeld. Back in 1975, when Rumsfeld was Gerald Ford's Defense Secretary--he's the only person to have held the job twice--he inherited the Pentagon's first attempt at a missile-defense shield, the $25 billion Safeguard system, designed to protect 150 Minuteman missiles dotting North Dakota.
But cost and technology woes plagued Safeguard. Rumsfeld, a onetime G.O.P. Congressman from Illinois, knew it. Even worse, the Soviets were rendering Safeguard useless by putting multiple warheads atop each of their missiles. After three months as Defense Secretary, under orders...