A tactical nuclear weapon (TNW) or non-strategic nuclear weapon is a nuclear weapon which is designed to be used on a battlefield in military situations, mostly with friendly forces in proximity and perhaps even on contested friendly territory. This is opposed to strategic nuclear weapons which are designed to be mostly targeted in the enemy interior away from the war front against military bases, cities, towns, arms industries, and other hardened or larger-area targets to damage the enemy's ability to wage war. Tactical nuclear weapons were a large part of the peak nuclear weapons stockpile levels during the Cold War.
Tactical nuclear weapons include gravity bombs, short-range missiles, artillery shells, land mines, depth charges, and torpedoes which are equipped with nuclear warheads. Also in this category are nuclear armed ground-based or shipborne surface-to-air missiles (SAMs) and air-to-air missiles.
Small, two-man portable, or truck-portable, tactical weapons (sometimes misleadingly referred to as suitcase nukes), such as the Special Atomic Demolition Munition and the Davy Crockett recoilless rifle (recoilless smoothbore gun), have been developed, although the difficulty of combining sufficient yield with portability could limit their military utility. In wartime, such explosives could be used for demolishing "choke-points" to enemy offensives, such as at tunnels, narrow mountain passes, and long viaducts.
There is no precise definition of the "tactical" category, neither considering range nor yield of the nuclear weapon. The yield of tactical nuclear weapons is generally lower than that of strategic nuclear weapons, but larger ones are still very powerful, and some variable-yield warheads serve in both roles, for example the W89 200 kiloton warhead armed both the tactical Sea Lance anti-submarine rocket propelled depth charge and the strategic bomber launched SRAM II stand off missile. Modern tactical nuclear warheads have yields up to the tens of kilotons, or potentially hundreds, several times that of the weapons used in the atomic bombings of Hiroshima and Nagasaki. Specifically on the Korean peninsula with a nuclear armed North Korea facing off against a NPT compliant South Korea there have been calls to request a return of US owned and operated short range low yield nuclear weapons, nomenclatured as tactical by the US military, to provide a local strategic deterrent to the North's growing domestically produced nuclear arsenal and delivery systems.