Article 9 of the Japanese Constitution (1946) states:
1) Aspiring sincerely to an international peace based on justice and order, the Japanese people forever renounce war as a sovereign right of the nation and the threat or use of force as means of settling international disputes.
2) In order to accomplish the aim of the preceding paragraph, land, sea, and air forces, as well as other war potential, will never be maintained. The right of belligerency of the state will not be recognized.
Under the constitution is was decided by the Supreme Court that although the ability of Japan to go to war should be curtailed, their ability to defend themselves should not. Thus Japan technically does not have a military but rather a strange entity called the Japan Self-Defence Force or JSDF.
Pacifists have long argued that there isn't really a difference between an attack or a defence force since the hardware is the same. The idea has been explored in other arenas too, most famously in the anime Neon Genesis Evangelion when the JSDF was deployed against megabeasts that may or may have not been alien.
Enter the USA.
The USA has maintained military bases in Okinawa since WW2. This of course hasn't contravened the constitution since the forces weren't being maintained by Japan.
After 3½ years of negotiations, Japan and the USA will finally reach an agreement to hand back these military bases. The government is expected to pass laws and secure funds to finalize the return of part of the air traffic control rights for the U.S. Air Force's Yokota Air Base in Tokyo to Japan by September 2008.
Foreign Minister Taro Aso and Defense Agency Director General Fukushiro Nukaga, and U.S. Secretary of State Condoleezza Rice and Defense Secretary Donald Rumsfeld attended the meeting.
The plan will not set a timetable for the return, but the two sides will work out a detailed plan for the handover by March 2007. Tokyo will shoulder USD6.09bn, or 59% of the total USD10.27bn cost for relocating the marines to Guam. The two sides will decide in October which part of the airspace over the Yokota base will be returned to Japan in 2008. In 2009, the two governments will finish talks on conditions for returning the entire airspace of the base to Japanese control.
To improve "cooperation" between the Self-Defense Forces and U.S. armed forces, the Air Self-Defense Force's Air Defense Command will be relocated to the Yokota base in 2010 and a joint task force for air defense and missile defense will be established.
A joint statement to be released separately from the final plan did not mention a review of the guidelines for defense cooperation, but included a clause calling for Tokyo and Washington to strengthen and improve bilateral security and the effectiveness of cooperation in international peace activities.
One wonders exactly how this is to be resolved under the constitution. The USA would obviously still like to maintain some presence in the area, but how does one sign a treaty with a nation who has no "military" forces? It's certainly vexhing for the lawmakers, since Article 9 was imposed by the USA themselves, and to suddenly ask for the constitution which they imposed to be ignored, smacks of international hypocracy.
Unless giant aliens like Gamera, Mothra, Godzilla or Angiurus invade.