High-level summits like Thursday's between U.S. President Barack Obama and Prime Minister Shinzo Abe are mostly scripted affairs, with a clearly defined agenda revolving around the most pressing, or politically important, issues.

The Japan-U.S. summit covered America's military commitments to Japan under the bilateral security treaty, including standing tough on the Senkakus and North Korea. They also covered the Trans-Pacific Partnership trade pact.

But in any summit, there are always pressing issues that are downplayed, left off the agenda or deemed not worthy of high-level attention.