This was Israel's thinking with Hamas - they're deterred, they're comfortable and in charge and they wouldn't do anything to jeopardise that, etc. Israel's thinking was wrong, and they've learned to believe their enemies when they say they want to destroy Israel. There isn't a country in the world that would allow their enemies, who have repeatedly stated that said country's demise is a key goal of theirs, to develop nukes if they have with the capability to stop it.