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.
World War III
Of the three nuclear powers in NATO (France, the United Kingdom and the United States), only the United States has provided weapons for nuclear sharing. , Belgium, Germany, Italy, the Netherlands and Turkey are still hosting US nuclear weapons as part of NATO's nuclear sharing policy. Canada hosted weapons until 1984, and Greece until 2001. The United Kingdom also received US tactical nuclear weapons such as nuclear artillery and Lance missiles until 1992, despite the UK being a nuclear weapons state in its own right; these were mainly deployed in Germany.