You could almost hear the collective "Aw, damn," from Japan's Ministry of Defense Friday as a North Korean missile broke up soon after takeoff and plopped into the sea. Japan spends about $5 billion a year on missile defense and had mobilized forces throughout the country to shoot the missile down if it strayed anywhere close to Japanese territory. It would have been the first shots fired in anger by the Japanese since World War II.

"this was not a political show. they were really serious and they would have tried to shoot it down if it came inside japanese territory," says takashi kawakami, a professor of international affairs and a military specialist at tokyo's takushoku university. the unha-3 rocket was expected to pass close by japan's southern islands. that includes okinawa, home to 1.4 million japanese and about 25,000 us troops. japan sent three of its four aegis-equipped kongoh-class destroyers and seven patriot pac-3 missile batteries to the region in preparation for the launch. to make sure no one missed the point, it also set up a patriot battery at the defense ministry compound in the heart of tokyo. that's a far greater response then in 2009, the last time north korea launched a missile in japan's direction. tokyo has been working on missile defenses since nuclear-armed north korea lobbed a long-range rocket over japan's main islands in a 1998 test. the government approved participation in missile defense research with the us defense department, and gave the go-ahead to a full co-development program in 2005. the u.s. and japan operate tracking sites throughout the country and earlier this year opened a new joint air defense command at yokota air base, near tokyo, to coordinate air and missile defenses. the aegis system uses a network of sensors and computers to track missiles and launch ship-based sm-3 missiles. it can also tie in with land-based pac-3 missiles. north korea said friday's launch was designed to put an earth-observation satellite in orbit, but most experts believe it was a test of ballistic missile technology. earlier tests in 2006 and 2009 were deemed failures, as well.