As the number of missile-wielding states grows and as the nuclear club expands, the likelihood of a missile being unleashed against the American people or their allies—whether by mistake, miscalculation, or a madman—also grows. Missile defense doesn’t eliminate the danger, but it does give us a fighting chance to confront it.

Some dismiss North Korea and Iran’s threat, but such a view ignores the devastating impact a high-altitude electromagnetic pulse (EMP) event could have on the United States.