The W78 is a type of thermonuclear warhead developed by the United States during the Cold War. It is designed to be deployed on the Minuteman III intercontinental ballistic missile (ICBM) system. The W78 has a yield of approximately 335 kilotons, making it significantly more powerful than the atomic bombs dropped during World War II. This warhead is part of the U.S. nuclear arsenal and plays a crucial role in the country's strategic deterrence policy. The W78 is currently undergoing modernization efforts to ensure its reliability and effectiveness in the future, reflecting ongoing concerns about global security and nuclear proliferation.