Japan: About 54,000 US military personnel, 42,000 dependants and 800 civil service employees at 85 facilities. Another 25,500 locals are employed as doctors or clerks, among other roles. South Korea: About 28,500 soldiers.
Japan: According to their bilateral pact, Japan has to bear the costs related to the hosting of US bases, while the US pays for maintenance and operational expenditures. But since 1987, Japan has been paying all the labour expenses and utility costs that were supposed to be covered by the US. The so-called "sympathy budget" peaked in 1999 and now stands at 192 billion yen (S$2.5 billion). Japan also pays for costs related to the realignment of US forces.
Japan's total tab comes up to about 377 billion yen this year, or 75 per cent of the total bill. South Korea: Under a five-year deal to share costs, inked in 2014, Seoul agreed to increase its share by 5.8 per cent to about US$867 million (S$1.2 billion) - or about 40 per cent of the total.
Seoul will also bear an unspecified amount of the costs of labour, logistics and construction of US bases. The total expenses add up to about 2.5 per cent of its defence budget.
ABOUT THE ALLIANCES
Japan: The US primarily sees its bases in Japan as crucial for the "forward deployment" of troops, and also sees the strategic imperative to buttress its presence in East Asia.
Under the Japan-US security accord, the US is obliged to defend Japan if the country is attacked. In return, Japan is mandated to let the US use its land, airspace and military bases to maintain "international peace and security in the Far East". South Korea: The US maintains its presence in Seoul to counter a belligerent North Korea, which has fired at least 20 ballistic missiles and conducted two nuclear tests this year.