Japan's cabinet has adopted a national security strategy and revised defence plans that increase spending and call for a larger role in maintaining international stability amid China's rise.
The programme for 2014-2019 includes acquisition of surveillance drones, anti-missile destroyers and other equipment as Japan's defence priority shifts from its northern reaches to the East China Sea, where Tokyo and Beijing are embroiled in a territorial spat over uninhabited islands.
The revised defence plans are based on the new national security strategy that reflects prime minister Shinzo Abe's drive to raise the profile of Japan's military and for the country to play a bigger international role.
Experts say the strategy and the defence plans are in line with power shift that has been continuing for several years. But Japan's neighbours - and some Japanese citizens - fear the guidelines push the country away from its pacifist constitution.
The guidelines say China's growing maritime and military presence in the East China Sea, its lack of transparency and "high-handed" approach - including its recent imposition of an air defence zone in the area - pose potential risks that could trigger problems.
Late last month China said all aircraft entering a vast zone over the East China Seat must identify themselves and follow Chinese instructions , although the US, Japan and South Korea have ignored those demands.
Mr Abe said the national security strategy showed Japan's diplomatic and security policy to people in and outside Japan "with clarity and transparency".
Under the plan, Japan is shifting its troop deployment from the north to remote islands in the south west and creates its first "amphibious" unit similar to the US Marines, as part of ground defence forces, to respond quickly in case of foreign invasion on those islands.
Japan plans to deploy early warning system, submarines and anti-missile defence system to step up intelligence in the area.
During the five-year period through March 2019, Japan plans to buy three drones, probably a Global Hawk, as well as 17 Ospreys and two Aegis-class destroyers. The purchases would cost 24.7 trillion yen (3151bn), up 5% from the previous plan.
The defence plan says Japan should "demonstrate its commitment to defence and its high capability", upgrade equipment, increase troop activity and step up defence capability in both quality and quantity to raise deterrence levels amid an increasingly harsh regional security environment.