https://www.vice.com/en_us/article/g5ymaw/did-israel-finally-confirm-it-has-nuclear-weapons-by-threatening-gaza

On Sunday, Israeli Prime Minister Benjamin Netanyahu indefinitely suspended Heritage Minister Amichai Eliyahu from cabinet meetings after Eliyahu said nuking Gaza was “one of the possibilities” Israel could use in its ongoing bombardment of the Palestinian territory. It was a shocking comment for many reasons, one of which being that Israel having nuclear weapons is an open secret—but one that its government has never officially confirmed. 

“Analyzing Israel's nuclear arsenal is fraught with uncertainty, not least of which because Israel purposefully does not publicly acknowledge its own possession of nuclear weapons,” Matt Korda, a senior research fellow at the Nuclear Information Project, told Motherboard. “To the best of our knowledge, and based on assessments of satellite imagery, delivery systems, and fissile materials, they have a stockpile of approximately 90 warheads––although this estimate comes with considerable uncertainty.”