Japan has deployed their own Patriot PAC-3 Missle defense batteries Friday at Iruma airbase in Saitama Prefecture. This is a full year ahead of the announced date, and will certainly give North Korea something to think on. From Spacewars:
Kyodo also noted that while the current Patriots are deployed as an integrated part of Japan’s own armed forces, U.S. forces last October deployed PAC-3 missiles at the U.S. Kadena Air Base on the Japanese island of Okinawa, the main U.S. military base in the region. Each Patriot PAC-3 launcher can fire up to 16 missiles, the Japanese news agency said.
Tokyo is not betting on the Patriot alone. It has also purchased U.S.-built Standard Missile-3 interceptors to be fired from warships, and hopes top have its first warship armed with them operational by the end of this year. SM-3s are designed for higher level interception of incoming ballistic missiles, though not to intercept extremely fast flying intercontinental ballistic missiles, or ICBMs. Patriots are designed for low level close range interception.
This will put two layers in place, and further development of the US GMD systems and other initiatives will put the rest of the needed missile defense layers in place.