Nuclear triad
Israel is known to have nuclear-capable aircraft and land-base missiles, with the addition of nuclear-armed submarines this would mean that they now have a full triad of land-, air-, and sea-based nuclear delivery systems some of which would be invulnerable to a first strike by an enemy for the first time in their country's history. No other nation in the Middle East in known to be in possession of nuclear weapons, even though Iran, Iraq, Syria and Libya have started development programs that were never completed.
2010 NPT Review Conference
The Nuclear Nonproliferation Treaty (NPT), which entered into force in 1970, recognizes five countries as nuclear-weapon states (the United States, Russia, the United Kingdom, France, and China), who commit to pursue disarmament, and the right of other signatories to use nuclear technology for peaceful purposes, conditional upon their non-acquisition of nuclear weapons. Its ratification is nearly universal because it is adhered by 189 states, including five nuclear-weapon states, with the exception of Israel, India, and Pakistan. North Korea left the NPT and tested its first nuclear weapon in 2006.