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.
Taiwan and weapons of mass destruction
The development of nuclear weapons by the Republic of China has been a contentious issue, as it had been triggered by PRC's first nuclear test in 1964. The U.S., hoping to avoid escalating tensions in the Taiwan Strait, has continually opposed arming the Republic of China with nuclear weapons after 1979. Accordingly, the Republic of China adheres to the principles of the nuclear Non-Proliferation Treaty and has stated that it does not intend to produce nuclear weapons, on the official basis. Past nuclear research by the ROC makes it a "threshold" nuclear state.