Every six months, the intelligence agencies provide Congress with a report on technology acquired by foreign states that's "useful for the development or production of weapons of mass destruction". These reports discuss the programmes in India, Pakistan, North Korea, Iran and other nations, but not in Israel. Whenever other states have tried to press Israel to join the nuclear non-proliferation treaty, the US and European governments have blocked them. Israel has also exempted itself from the biological and chemical weapons conventions.
By refusing to sign these treaties, Israel ensures it need never be inspected. While the International Atomic Energy Agency's inspectors crawl round Iran's factories, put seals on its uranium tanks and blow the whistle when it fails to cooperate, they have no legal authority to inspect facilities in Israel. So when the Israeli government complains, as it did last week, that the head of the IAEA is "sticking his head in the sand over Iran's nuclear programme", you can only gape at its chutzpah.
When the west pressures Iran to meet it's commitments under the NNPT - ignoring the fact that the Iranians are allowed to enrich uranium under the NNPT for civilian purposes - we are also ignoring the elephant in the room, which is Israel's nuclear arsenal.
Until we become serious about our commitments under the NNPT, then we are simply spouting hypocrisy when we demand that others adhere to a treaty which we ourselves are blatantly ignoring.
And by allowing Israel to continue to refuse to sign up to the NNPT, we are making a joke out of our supposed desire for a world free of nuclear weapons.