But I didn´t know why this hoax was put out at that time. Here might be the reason:
The Pentagon is reportedly speeding up plans to deploy advanced Patriot interceptor missiles on U.S. bases in Japan for the first time, a countermeasure seen as a response to the increasing threat of North Korean missiles.
The Japanes didn´t really want those missiles to be stationed in Japan. The public opinion is against further US forces. So a bit of show was needed...
China's gonna be pleased no?
Also see:
A test missile fired from Hawaii was knocked down by a ship-based interceptor, using a Japanese ship for radar tracking. Officials say it's been planned for months, just happens to be coincidence that the test takes place in the Pacific with Japan's assistance, while North Korea threatens to test a new long-range missile, and some call for a strike against the missile...