With defense and trade issues still to be resolved, the summit from Thursday in Tokyo between Prime Minister Shinzo Abe and U.S. President Barack Obama is a high-stakes game for both sides.

Foremost for Prime Minister Shinzo Abe, it is a test of the military alliance with the United States, the cornerstone of his overall diplomatic strategy and the best hope for keeping China in check.

For Obama, it is a chance to appear the master statesman in the face of criticism that he failed to rise to the challenge in both Syria and Crimea, as well as demonstrate his avowed commitment to stay engaged in Asia, observers say.