Debt of Honor is a novel by Tom Clancy. It is a continuation of the series featuring his character "Jack Ryan". In this instalment, Ryan has become the National Security Advisor when the Japanese government (controlled by a group of corporate tycoons) goes to war with the United States. In an attempt to cripple the U.S. Navy (as part of a grand plan involving China and India to radically alter the global power balance), the Japanese attack American submarines and ships and occupy American-held Pacific islands.

Again, with the derring-do of various parts of the armed forces, under the wise direction of the President (with Ryan's advice), the U.S. prevails over the forces of evil.

After the real-life September 11, 2001 Terrorist Attack, the book will be largely be remembered for its prophetic conclusion, in which an embittered Japanese airliner pilot crashes his 747 into the Capitol building during a joint session of Congress with the President attending. This paves the way for Ryan, who has just been appointed Vice-President, to become President in the next book, Executive Orders.