Israel is internationally recognised as a nuclear power, but has never formally confirmed or denied that it has nuclear weapons. Its arsenal is considered to amount to some 200 warheads, which could be delivered by aircraft, missile or one of its three submarines.
Israel is thought to have begun its nuclear programme in secret in the early 1950s, and produced its first bomb in 1967. In 1986, the whistleblowing disclosures of former nuclear scientist Mordechai Vanunu revealed a programme larger and more advanced than previously thought.
Concerns over reaction in the Arab world, the potentially negative response from elements of the Israeli public, and consideration of America's commitment to non-proliferation have all been cited as reasons why Israel has never publicly disclosed its nuclear capabilities.