I agree with what alot has been said. China is not our sworn enemy. They are a country, however, that we need to be cautious of. Why? Becuase they continue to threaten the democracy that is Tiawan, and they are building up there military at a fast pace. Our biggest threat is Iran and North Korea. North Korea does not have a strong enough military to defend themselves. In comparison, North Korea spends 2.5 billon a year on their military, the U.S spends 400 billion. North Koreas army is all show, no substance. The threat comes when we attack North Korea, they will attach our friend and ally the south Koreans. North Korea is less than hundred miles from downtown Seoul. That would be a catastrophe if they lobbed missiles into the South.
As far as Iran, there has been alot of talk that they want nuclear weapons, blah blah. according to the U.N, it would take Iran almost 10 years to develop a nuclear weapon, but still have no means to deliver it. Again in comparison to the U.S, we have literally hundreds of nuclear weapons, with the means to delieve them anywhere in the world.
The U.S Army training the Japanese army, I think, is just two allies training together. Nothing more.