Japan is one of the most active cooperating partners with the US on missile defense development. In its strategic doctrine Japan prefers to be self-reliant when it comes to defense and devotes considerable resources to research and development.
In December of 2011 the Japanese government initiated a significant development to further US-Japan cooperation in missile defense by relaxing the three principles on arms exports, allowing the US to transfer a jointly developed missile defense system to third countries, provided that transfer benefit Japan's national security.
Following its landslide victory over the DPJ in the December 2012 Lower House election, the LDP is set to issue a new National Defense Program Guideline by the end of 2013.
has 2 radar and 2 optical satellites for space defense. Japan also
has Patriot PAC-3 missile batteries, Army/Navy SPY-1 radar (AN/TPY-2), FPS-5 and FPS-3UG ground based radars,
and sea-based Aegis BMD naval destroyers. The Japan Maritime Self Defense Force has two classes of Aegis configured destroyers, the KONGO Class and ATAGO Class, both armed with SM-3 Block IA missiles.