Peace through strength is the doctrine that military strength is a primary or necessary component of peace. This is sometimes taken to mean world peace, and sometimes taken to mean peace for the possessor of the military strength. This doctrine is a major justification cited for large militaries, and also served as the primary motivation behind the Cold War doctrine of mutually assured destruction.

The concept arouses a great deal of controversy. On the one hand, many especially in the military believe this doctrine and it is responsible for the motto of the United States Air Force, Peace is our profession and on the naming of the Peacekeeper missile. On the other hand, opponents of the concept argue that the doctrine is merely a form of doublespeak and a justification for militarism.

The notion of peace through strength is a very important part of both modern and traditional Chinese strategic thought, and was first formalized by Sun Tzu. The complexity of this doctrine can be seen by reactions to Chinese military modernization, which in the view of the Chinese leadership is merely the implementation of this doctrine, while to other powers such as the United States this modernization may look threatening.