Intermediate-range ballistic missile

An intermediate-range ballistic missile (IRBM) is a ballistic missile with a range between 3,000 and 5,500 kilometres (1,900–3,400 mi), categorized between a medium-range ballistic missile (MRBM) and an intercontinental ballistic missile (ICBM). Classifying ballistic missiles by range is done mostly for convenience. In principle there is little difference between a high-performance IRBM and a low-performance ICBM, because decreasing payload mass can increase the range over the ICBM threshold. The range definition used here is used within the U.S. Missile Defense Agency.