The United States may be a dominant military force in Asia for now but short of going to war, it will be unable to stop its economic and diplomatic clout from declining relative to China’s power. That’s the view of Australian think tank the Lowy Institute, which on Tuesday evening released its 2019 index on the distribution of power in Asia. However, the institute also said China faced its own obstacles in the region, and that its ambitions would be constrained by a lack of trust from its neighbours.