"Debt of Honor" by Tom Clancy is a political thriller novel that tells the story of Jack Ryan, a former Marine and CIA analyst who becomes the President of the United States. As President, Ryan faces a range of challenges, from economic and political crises to military conflicts and terrorist threats. However, his greatest challenge comes when a group of Japanese extremists launch a surprise attack on the United States, killing thousands of people and causing widespread destruction. As Ryan and his team of advisors work to respond to the crisis, they uncover a larger conspiracy that threatens to plunge the world into chaos. The novel explores themes of international relations, military strategy, and political power, and is praised for its detailed research, complex characters, and suspenseful plot. It is considered one of Clancy's most influential and popular works, and has had a significant impact on the genre of political and military thrillers.