TOKYO With North Korea planning to launch a long-range rocket early next month that will pass over Japan's territory, Tokyo is preparing to intercept any debris that might fall on the country.
Following are questions and answers about Japan's reaction to the planned launch, which Tokyo, Washington and Seoul see as a disguised long-range missile test. North Korea says it plans to put a satellite into space:
WHY IS JAPAN SO CONCERNED?
Tokyo will have around 10 minutes notice if a missile or debris threatens its territory.
The first booster rocket is expected to fall into the Sea of Japan and the second into the Pacific Ocean, but a failed launch or accident could result in one of the stages of the rocket, or bits of it, falling on Japan and endangering lives and property.
IS JAPAN OR THE U.S. CAPABLE OF INTERCEPTING IT?
Japan has interceptors theoretically capable of shooting down a missile aimed at its territory, but analysts are divided on whether it can intercept free-falling debris that may fall toward Japan.
Japan has two Aegis-equipped destroyers carrying Standard Missile-3 (SM-3) interceptors capable of shooting down a ballistic missile outside the Earth's atmosphere.
Six ground-based Patriot Advanced Capability-3 (PAC-3) interceptors provide back-up protection as the missile returns to earth.
U.S. satellites can distinguish between orbital and sub-orbital launches of long-range rockets in three minutes or less, analysts say, and if the rocket is directed at Alaska or Hawaii, the closest U.S. territory, interceptors based in Alaska and California could be used.
U.S. military commanders say they are confident they can shoot down a ballistic missile headed toward U.S. soil.
IS JAPAN LIKELY TO TRY INTERCEPTION?
Japan's pacifist constitution does not allow it to intercept a missile if it is clearly heading elsewhere. But it would try to shoot down a missile aimed at Japanese territory and might try to intercept any debris that falls toward Japan.
The potential risks of shooting down the rocket in flight are enormous, because North Korea has warned it would see such a move as an act of war.
Tokyo is expected to clear the way for an order by the defense minister to ready the military to destroy any falling object that poses a threat to Japan -- a necessary legal step.
Some analysts have dismissed Tokyo's move to prepare for possible interception as diplomatic posturing.
WHAT WOULD A SUCCESSFUL NORTH KOREAN TEST MEAN FOR JAPAN?
If the North's planned launch succeeds, Tokyo is likely to enhance its existing missile defense system.
Japan's efforts to develop its missile defenses in cooperation with Washington have accelerated since 1998 when the North's firing of a missile over Japan stunned the region.
But given the huge debt that limits its fiscal resources, Japan's defense budget is unlikely to increase rapidly, especially when Tokyo is focusing on economic stimulus.
WHY ARE JAPAN-NORTH KOREA TIES SO BAD?
Ties have been plagued by problems stemming from Japan's colonial rule over the Korean peninsula in the early 20th Century, under which many Koreans suffered.
For Japan, the dispute over Japanese abducted by North Korean agents decades ago is an emotional issue and a major obstacle to establishing diplomatic ties between the two, in addition to worries about the North's missile and nuclear programs.
WHAT DIPLOMATIC ACTION WOULD JAPAN TAKE?
Currently a non-permanent member of the U.N. Security Council, Japan would likely raise the issue at the council, saying the North's launch would violate an existing resolution. But it is unclear if Tokyo can rally support for sanctions or even a strong condemnation.
Japan's current sanctions on the North, including an import ban, expire on April 13. In addition to extending them, Tokyo may introduce a ban on exports, as proposed by a ruling party panel.
WHAT RISKS ARE THERE FOR JAPAN PREMIER ASO?
For unpopular Prime Minister Taro Aso, who must call an election by October, the launch could provide an opportunity to demonstrate leadership and good crisis management skills.
Any signs of mismanagement or dithering could hurt his already low support ratings.
(Additional reporting by Jim Wolf in Washington; Editing by Isabel Reynolds and David Fox)