Nuclear weapons delivery is the technology and systems used to place a nuclear weapon at the position of detonation, on or near its target. All nine nuclear states have developed some form of medium- to long-range delivery system for their nuclear weapons. Alongside improvement of weapons, their development and deployment played a key role in the nuclear arms race.
Strategic nuclear weapons are intended primarily as part of a doctrine of deterrence by threatening large targets, such as cities or military installations. These are generally delivered by some combination of land-based intercontinental ballistic missiles, sea-based submarine-launched ballistic missiles, and air-based strategic bombers carrying gravity bombs or cruise missiles. The possession of all three is known as a nuclear triad.