[quote=shadowkiller912]
Huh, interesting.What is your opinion on what would happen to Japan?
[/quote]

It's honestly a fairly xenophobic nation with a shrinking population, and there's been no suggestion they'd change their immigration policy to let in non-Japanese as actual citizens and not residents on a work visa. They crowding of the islands and the centuries of using it much of its natural resources would imply that if they could raise an army it wouldn't be offensively built.

Their capabilities to defend themselves may as well rely on UAVs or ground-based counter-parts. A decline in work-age young men and women would also likely mean that'd there'd be a greater demand within China for autonomous manufacturing as provided in 3d printing. Which I imagine would keep the status quo of "The Japanese man living at work and commuting to home".

Even if/when the Japanese ammend their constitution to allow for a more proactive role in war and to be a proactive military party in any theater they'll need to deal with nations who have a far more fleshed out modern military tradition. Japan hasn't seen a major conflict since they were disarmed in the Second World War and picked up their current Pacifist constitution. And not only would China out manpower them, but out experience them on the field. The Japanese would be reliant on others to help them enforce their war goals, which would likely end up as minor gains and nothing significant. I imagine they'd be lucky to get their land disputes with Russia, Korea, and China resolved (Which'd involve such things as the Kuril Islands held by Russia, some shitty rocks called the Liancourt rocks now held by Korea, and the Senkaku Islands as both claims by PRC and Taiwan).