President Barack Obama will leave the country for a four-nation tour of Asia starting Wednesday despite a host of domestic concerns, including the massacre at Fort Hood, a sharply rising jobless rate, his health care legislation stalled in the Senate and his Afghanistan troop decision still pending. He planned his Nov. 11-19 trip around the annual Asia-Pacific Economic Cooperation meeting in Singapore, but added stops in Japan, China and South Korea. The itinerary reflects the growing importance of East Asia — especially China — to everything from financing U.S. debt and powering the global economic recovery to climate change, disease...