IRBM

Intermediate-Range Ballistic Missiles (IRBMs) fill the gap between medium-range missiles used for theater strikes and intercontinental ballistic missiles designed for global reach. With ranges between 3,000 and 5,500 kilometers, IRBMs can threaten targets across entire regions, for example, a Chinese IRBM launched from the mainland can reach U.S. bases in Guam, Japan, or the Philippines.

IRBMs were at the center of the Cold War's most dangerous crisis. The Soviet Union's deployment of SS-4 IRBMs to Cuba in 1962 brought the world to the brink of nuclear war because these missiles could reach most of the continental United States with only minutes of warning. The resolution of the Cuban Missile Crisis led directly to arms control agreements that eventually banned an entire class of nuclear missiles.

The Intermediate-Range Nuclear Forces (INF) Treaty of 1987 eliminated all U.S. and Soviet ground-launched ballistic and cruise missiles with ranges between 500 and 5,500 kilometers. The treaty's collapse in 2019, driven by alleged Russian violations and China's unconstrained IRBM buildup, has reopened this category of weapons. China's DF-26, with a range of approximately 4,000 kilometers and the ability to carry conventional or nuclear warheads, is the most prominent IRBM in service today.