If the mistake is in reference to America and Vietnam, it looks like the JSDF is making the exact same mistake that America made. The JSDF are starting another conflict and are creating/supporting a new government, that sounds like the basis to the Vietnam War to me. So I'm not actually sure what mistake is not meant to be made?
Really for America I think the mistake in entering the war in Vietnam was not having the commitment to actually win it, like bombing and invading North Vietnam. Jungles and mountains don't help either.