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You are here: Home / Europe / Fact Sheet: The Basics of Nuclear Weapons

July 21, 2012

Fact Sheet: The Basics of Nuclear Weapons

Prepared by Candice DeNardi

Updated by Bridget Nolan and Kingston Reif

What is a Nuclear Weapon?

  • A nuclear weapon is a device which rapidly releases nuclear energy, either through fission (as in the bombs dropped on Hiroshima and Nagasaki) or a combination fission and fusion (as in a thermonuclear or hydrogen bomb).

How do Nuclear Weapons differ from Conventional Weapons?

  • Nuclear weapons use fissionable materials to fuel an explosion, whereas conventional weapons do not. Only a relatively few radioactive materials are fissionable, such as Plutonium-239 or Uranium-235. In addition to their sheer destructive power, nuclear weapons also threaten human life through the radioactive fallout they disperse.

Brief History of Nuclear Weapons

  • The United States tested the first atomic weapon on July 16, 1945 (the “Trinity Test”). One month later, the U.S. dropped the “Little Boy” and “Fat Man” nuclear bombs on Hiroshima and Nagasaki.
  • The Soviet Union tested its first nuclear device in 1949. At its peak in the 1960s, the United States maintained approximately 30,000 nuclear warheads; during the 1980s, the Soviet Union had over 40,000. Today the United States possesses a total inventory of approximately 8,000 warheads. Russia possesses a total inventory of approximately 10,000 warheads. Together the United States and Russia possess over 90% of the approximately 19,000 nuclear warheads on the planet.
  • There are now nine states that possess nuclear weapons—the United States, Russia, the United Kingdom, France, China, India, Pakistan, Israel and North Korea.
  • The Nuclear Non-Proliferation Treaty (NPT) has 189 signatories and came into force in 1970. It calls upon the five recognized nuclear weapons states—the United States, Russia, the United Kingdom, France, and China—to in good faith work towards disarmament, while recognizing that all non-nuclear weapons states have an inalienable right to the peaceful uses of nuclear energy technology. The NPT has three basic pillars: nonproliferation, the right of all nations to peaceful nuclear technology, and disarmament.
  • Israel Pakistan and India are non signatories of the NPT, and North Korea withdrew from the treaty in 2003.

Delivery Methods

  • Missiles: Nuclear warheads can be delivered on short, intermediate, or long-range (intercontinental ballistic missile—ICBM) missiles.
  • Bombers: The majority of nuclear weapons dropped from bombers such as the US B61, are gravity bombs. Nuclear weapons can also be delivered from bombers as air-launched cruise missiles.
  • Submarines: Equipped submarines (SSBNs) can deploy submarine launched ballistic missiles (SLBMs).
  • The United States deploys all three delivery systems in its nuclear arsenal, which is referred to as a nuclear triad. Not all nuclear armed-states deploy their forces in this way. For example, France only deploys bombers and submarines.
  • US nuclear weapons are supported by an extensive network of command, control, communications, and intelligence (C3I) assets. These assets provide warning of a nuclear attack, facilitate the execution of orders to use nuclear weapons, and more.
  • A nuclear device could also be delivered by other means, such as via a suitcase or a backpack. Terrorists are especially likely to employ these delivery methods.

What Is the Difference Between Tactical (or Non-strategic) and Strategic Weapons?

  • Tactical or non-strategic nuclear weapons are generally characterized by a lower yield and shorter range than a long-range (strategic) nuclear weapon. Strategic nuclear weapons are delivered by long-range delivery systems (ICBMs, SLBMS, long range bombers) and targeted against strategic assets such as an adversary’s strategic nuclear weapons arsenals and storage sites, strategic military bases, strategic weapons production centers, leadership, and population centers.

Posted in: Europe, Factsheets & Analysis on Nuclear Weapons, France, Issue Center, Nuclear Weapons

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