国防入门：战略核力量

https:/crsreports.congress.gov Updated May 1,2025Defense Primer:Strategic Nuclear ForcesThe United States is in the process of modernizing its strategic nuclear forces.This modernization effort includes numerous Department of Defense(DOD)major defense acquisition programs,some of which are annually assessed by the Government Accountability Office,and warhead modernization programs implemented by the National Nuclear Security Administration(NNSA),a semi-autonomous agency in the Department of Energy.In 2025,the Congressional Budget Office estimated that U.S.programs to operate and modernize nuclear forces would cost$946 billion over the next 10 years.The FY2025 DOD budget requested“$49.2 billion for the modernization,sustainment,and operations of all three legs of the nuclear triad.”Members of Congress have shown strong interest in conducting oversight of U.S.nuclear modernization efforts.The Nuclear Triad Since the early 1960s,the United States has maintained a“triad”of strategic nuclear delivery vehicles.These include long-range land-based intercontinental ballistic missiles(ICBMs),long-range submarine-launched ballistic missiles(SLBMs)on strategic nuclear submarines(SSBNs),and lo