So, reading about the Cold War era I got to the point of nuclear powers, and was surprised to see that Israel never admitted up until today having nuclear weapons. It is stated in multiple books and online that Israel is 5/6th country to have nuclear weapons, between 1960s and 1970s (so either before or after China). Furthermore, there is an even Vela Incident in 1979 that most historians and scientist see as a clear nuclear test.
My question is why would Israel hide it? Looking through all wars between Israel and Arab powers - wouldn't being "known" as nuclear power during the Cold War help them to establish themselves in Middle East easier? What is world stance to this problem, especially the United States as being an important ally to Israel? Do we know by any chance did Israel ever think about using its nuclear weapon?
The US in the 1960s tried to strongly discourage Israel from getting nuclear weapons, because it feared that it would lower US freedom of action in the Middle East and increase the possibility of a Middle Eastern arms race. Israel did it anyway, going to great lengths to deceive US inspectors.
By the 1970s, it was clear to the Americans that the Israelis had nuclear weapons and weren't going to give them up. But they still didn't want other nations in the Middle East to pursue their own nuclear weapons, and had passed laws that basically said that the US won't cooperate militarily with nations that are in violation of the Nuclear Non-Proliferation Treaty. So this put the US and Israel in a bind. Israel didn't want to give up its nukes, and the US didn't want to abandon Israel as a military ally in the region.
The compromise was an agreement, negotiated by the Nixon administration, in which it was agreed that Israel would not "introduce" nuclear weapons into the Middle East. What does "introduce" mean? The US and Israelis hammered out a fig-leaf of an agreement: if you haven't tested a nuclear bomb, and you don't acknowledge you have a nuclear bomb, and you don't threaten anyone with a nuclear bomb — do you really have a nuclear bomb? Have you really "introduced" them into a region? Or are they all just hypothetical, on paper?
This is obviously quite inadequate, but it worked for diplomatic reasons. As a result, Israel cannot acknowledge its nuclear arsenal without running afoul of US laws, and exposing the US to charges of hypocrisy and willing subversion of the NPT regime. On the other hand, everyone knows Israel has nuclear weapons — they haven't been perfect about covering it up at all. So this policy of "nuclear opacity," in which Israel does not confirm or deny its nuclear arsenal, but everyone knows it has them, does two things: it satisfies a diplomatic relationship with the US, while also giving Israel the deterrent power of the weapons (since everyone knows they have them).
The fact that Israel has been known to be in flagrant violation since the mid-1980s (the Vanunu releases) has arguably weakened the power of this arrangement, as has their possible involvement in a test, and indeed there are many who claim that Israel should just admit to what everyone knows, and of course other nations in the Middle East (Iran, Saudi Arabia, perhaps more) are interested in nuclear weapons in part as a counter. So whether this policy has been successful is a different question.
Avner Cohen's book, The Worst-Kept Secret, is a great place to read more about these policies.
Hi there -- u/restricteddata has written on this topic before. Not discouraging further answers, but this post in particular may be of some interest to you.