Japan is changing its defence policy in response to the shifting balance of power in Asia, analysts say.
Forces will be bolstered in the southern islands, near to China and its growing military might.
Defences will be scaled down in the north, where they have been deployed since the Cold War to counter an invasion from Russia.
Tanks will be cut by a third, but Japan's submarine fleet will be expanded and fighter jets upgraded.
The guidelines also describe North Korea's missile and nuclear programmes as a "pressing and serious destabilising factor".
In response, more Patriot interceptor batteries will be deployed across Japan, and the number of warships which can shoot down missiles will be increased.
Japan's military is bigger than the UK's, but is forbidden by the country's constitution from offensive action.
The new strategic stance will be closely watched in Asia, where Japan's World War II aggression has been neither forgotten nor forgiven.
Relations between Japan and China deteriorated sharply in September, after collisions between a Chinese trawler and Japanese patrol boats near a chain of disputed islands in the East China Sea.