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.
Southeast Asian Nuclear-Weapon-Free Zone Treaty
The SEANWFZ treaty has a protocol that is open to signature by the five recognized nuclear-weapon states: China, France, Russia, the United Kingdom, and the United States. The protocol commits those states not to contribute to any violation of the treaty and not to use or threaten to use nuclear weapons within the zone.