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.
U.S. nuclear weapons in Japan
In December 2015 the United States Government acknowledged officially for the first time that it had stored nuclear weapons in Okinawa prior to 1972. That U.S. nuclear weapons had been located in Okinawa had long been an open secret. The fact had been widely understood or strongly speculated since the 1960s and was subsequently revealed by the U.S. military in apparently unnoticed photographs of nuclear weapons and delivery systems on Okinawa that were declassified and released to the U.S. National Archives in 1990.