Wolf Blitzer delivers the most important breaking news and political, international, and national security stories of the day. Tune to The Situation Room weekdays 5-7pm ET on CNN.
A zone of a couple hundred square miles in the East China Sea is at the heart of growing tensions between China and its neighbors South Korea and Japan, along with the U.S. CNN's René Marsh explains what an air defense zone is and why the U.S. does not recognize the one China declared just last week.
CNN's Tom Foreman looks at whether North Korea's claims that it can strike U.S. bases in Japan and Guam are realistic.
RELATED STORY: North Korea warns that U.S. bases in Guam, Japan are within range
The damage is not radioactive but the debris field still poses a danger to marine life as it inches toward North America.
RELATED STORY: Preparing for tsunami debris, wherever it may make landfall
Millions of tons of debris washed out to sea by the Japanese tsunami is headed for the U.S. CNN's Chad Myers reports.
RELATED: Tsunami debris at Hawaii by 2013? Researchers seek more precision