With North Korea threatening to send a salvo of ballistic missiles close to a US military hub in the Pacific, pressure could grow for Washington to put its multibillion-dollar missile defense system into use and shoot them out of the air before they can pose a real threat.
But should it? Could it?
That's no easy call.
North Korea claims it is in the final stages of preparing a plan to launch four intermediate-range ballistic missiles over Japan and into waters just off the island of Guam, where about 7,000 US troops are based. Guam is a launching point for US strategic bombers that the North, virtually flattened by US bombs during the 1950-53 Korean War, sees as particularly threatening. US bombers have flown over the Korean Peninsula several times to show American strength after Pyongyang's missile tests. Unlike past missile launches that landed much closer to North Korean territory, firing a barrage toward Guam would be extremely provocative, almost compelling a response. Trying to intercept the missiles, however, would open up a whole new range of potential dangers.
Here's the calculus of the pros, cons and conclusion.