Editor’s Note: More than four years since U.S. President Barack Obama's administration announced its "pivot to Asia" — a strategic rebalancing effort centered in large part on increased engagement with Southeast Asia — the White House is looking to breathe new life into the initiative. On Feb. 15-16, Obama is hosting regional leaders from the 10-member Association of Southeast Asian Nations (ASEAN) at a special summit at Sunnylands, Calif. — the first-ever standalone meeting with the bloc on U.S. soil. Southeast Asia is a region defined by the divide between the integrated mainland portion on the peninsula and the network of archipelagos stretching from Indonesia to the Philippines. ASEAN loosely ties these disparate nations together into a single regional bloc. But differences in economic and strategic imperatives among its members historically have undermined the bloc's unity and limited its power, preventing greater cooperation with outside powers, including the United States.