Japan began exercises Monday with the U.S. Army in Hokkaido, a day after it started naval maneuvers with Russia 800 km away off the coast of Vladivostok.
The drills illustrate the balance Prime Minister Shinzo Abe must strike between his attempts to mend relations with Russia and the need to bolster his country's alliance with the United States as a backstop to a more assertive China in the region.
While Russia supplies about 10 percent of Japan's natural gas needs, and potentially more, Japan has backed Group of Seven sanctions over Russia's infiltration of Ukraine. That sparked recriminations from Russia and raised military tensions, with Japanese jets scrambling hundreds of times to head off approaches by Russian aircraft in the three months through June.