U.S. President Barack Obama will meet with leaders of 10 Southeast Asian nations next week in a bid to coordinate American interests ranging from security to trade with a region increasingly sandwiched between Washington and Beijing. As WSJ's Ben Otto reports:

Participants in the two-day summit that begins Monday in southern California will discuss business and trade ties, terrorism and regional irritants such as Beijing’s disputed territorial claims in the South China Sea, U.S. officials said. The summit, which these people said will be informal and less scripted than a normal summit, come as the U.S. and China,...