(HANOI, Vietnam) — President Barack Obama’s mission in Vietnam and Japan is to build stronger economic and security ties with Asian-Pacific allies anxious about the rise of an increasingly muscular China. That forward-looking message will be delivered even as he confronts the legacies of two wars long past — Vietnam and World War II — that still are fraught with emotion. Obama’s first stop on his weeklong Asia trip was Vietnam, where he is the third sitting president to visit since the end of the war.