An intercontinental ballistic missile (ICBM) is a ballistic missile with a range greater than , primarily designed for nuclear weapons delivery (delivering one or more thermonuclear warheads). Conventional, chemical, and biological weapons can also be delivered with varying effectiveness, but have never been deployed on ICBMs. Most modern designs support multiple independently targetable reentry vehicle (MIRVs), allowing a single missile to carry several warheads, each of which can strike a different target. The United States, Russia, China, France, India, the United Kingdom, Israel, and North Korea are the only countries known to have operational ICBMs.
Early ICBMs had limited precision, which made them suitable for use only against the largest targets, such as cities. They were seen as a "safe" basing option, one that would keep the deterrent force close to home where it would be difficult to attack. Attacks against military targets (especially hardened ones) still demanded the u