American troops deployment in Asia Pacific

South KOREA 

South Korea said on Sunday it would pay 920 billion won ($866 billion, 634 million euros) in 2014 toward the growing cost of the US' military presence in the country.

Officials struck a deal to share the costs over the next five years as Washington prepares to send more troops and tanks to the country as part of an effort to shift its military emphasis toward Asia and away from Europe. 

There are currently some 28,000 US troops stationed in South Korea, the legacy of the 1950 to 1953 Korean War
(http://www.dw.de/south-korea-agrees-budget-hike-to-keep-us-troop-presence/a-17356540)

JAPAN

JAPAN Despite periodic outbursts of opposition to nuclear ship home-porting or other aspects of the U.S. deployment in Japan, support among the Japanese people for the security relationship has remained at a remarkably high level. As a result the U.S. has had a relatively free hand in the use of our facilities and in the deployment of forces there. Generations of Japanese leaders have cooperated with U.S. security needs. These include a contribution of $13 billion in support of the first Gulf War, the dispatch of ground forces in support of our operations against Saddam Hussein, and generous foreign assistance to many places in which we have a strategic interest, including Afghanistan. Japan has also for the past 25 years made major contributions - $4-5 billion per year - to the support of U.S. forces in Japan. Who would have imagined 60 years ago that there would be significant U.S. military facilities in Japan in 2010? (http://www.brookings.edu/research/opinions/2010/05/east-asia-breer)

(http://www.brookings.edu/research/opinions/2010/05/east-asia-breer)

Philiipines In fact, it’s quite possible the Americans will take an active role if China were to attempt to take over all the Spratly Islands. China already controls several of them. In keeping with its claim to the entire South China Sea, China also challenges not only the Philippines but also Vietnam, Malaysia and Taiwan, that is the anti-communist Republic of China, for control of the rest of the Spratlys. In Manila U.S. military officers and diplomats are talking to Philippine officials about setting up facilities on small islands near the long southwestern Philippine island province of Palawan, the closest jumping off point to the Spratlys. That idea remains non-publicized for now while the spotlight shines on the return of much larger U.S. forces to Subic Bay, once America’s largest overseas naval base, and Clark, the largest overseas U.S. air base in its heyday. (http://www.forbes.com/sites/donaldkirk/2014/05/03/u-s-asian-allies-want-to-know-is-u-s-ready-to-go-war-with-china-over-island-disputes/) (http://www.brookings.edu/research/opinions/2010/05/east-asia-breer)