Vietnam talks trust with China, invites Japanese warship

By Martin Petty and Ben Blanchard HANOI/BEIJING (Reuters) - Vietnam agreed to build a "truly trustworthy" relationship with China on Friday during a visit to Hanoi by its President Xi Jinping, but at the same time invited Beijing's old rival Japan for joint military exercises and a visit to a sought-after port. The diplomatic flurry highlights the fragility of China's testy ties with its communist neighbor, and Vietnam's efforts to diversity its relations through new alliances with states locked