Why do they neither confirm nor deny possessing nuclear weapons?
Thier nukes are just fine, and well controlled. Considering they did not sign the NPT they are not bound by it.
So the UN can go pound sand.
"Israel insists there must first be a Middle East peace agreement before the establishment of a proposed regional zone free of weapons of mass destruction. Its rivals in the region argue that Israel's undeclared nuclear arsenal presents the greatest threat to peace in the region."
UN tells Israel to let in nuclear inspectors | World news | guardian.co.uk
Israel's alleged nukes are only a threat to those who would attack Israel.
That is assuming Israel even has nukes.