The more nuclear arms are lying around, the more the chances of them being used. So to persuade Iran to forgo nuclear weapons is a laudable objective. But for the United States, Britain and France to insist on it is hypocritical.

These Western powers have argued convincingly for decades that nuclear deterrence keeps the peace – and themselves maintain nuclear armories long after the cold war has ended. So why shouldn’t Iran , which is in one of the world’s most dangerous neighborhoods, have a deterrent too?

And where is the source of the threat that makes Iran, a country that has never started a war in 200 years, feel so nervous that it must now take the nuclear road? If Saddam Hussein’s Iraq , with its nuclear ambitions, used to be one reason, the other is certainly Israel, the country that hard-liners in the United States are encouraging to mount a pre-emptive strike against Iran’s nuclear industry before it produces bombs.

The United States refuses to acknowledge formally that Israel has nuclear weapons, even though top officials will tell you privately that it has 200 of them. Until this issue is openly acknowledged, America, Britain and France are probably wasting their time trying to persuade Iran to forgo nuclear weapons.

The supposition is that Israel lives in an even more dangerous neighborhood than Iran. It is said to be a beleaguered nation under constant threat of being eliminated by the combined muscle of its Arab opponents.

There is no evidence, however, that Arab states have invested the financial and human resources necessary to fight the kind of war that would be catastrophic for Israel. And there is no evidence that Israel’s nuclear weapons have deterred the Arabs from more limited wars or prevented Palestinian intifadas and suicide bombers.

Nor have Israel ‘s nuclear weapons influenced Arab attitudes toward making peace. In the 1973 Arab war against Israel and in the 1991 Gulf war, they clearly failed in their supposed deterrent effect. The Arabs knew, as the North Vietnamese knew during the Vietnam War, that their opponent would not dare to use its nuclear weapons.

Israelis say that they need nuclear weapons in case one day an opportunistic Egypt and Syria, sensing that Israel ‘s guard is down, revert to their old stance of total hostility and attack Israel. But, as Zeev Maoz has argued in the journal International Security, these countries keep to their treaty obligations.

Egypt did not violate its peace treaty with Israel when Israel attacked Syria and Lebanon in 1982. Syria did not violate the May 1974 disengagement agreement with Israel even when its forces were under Israeli attack. Nor did Egypt, Jordan and Syria violate their treaty commitments when the second Palestinian intifada broke out in September 2000.

Since its 1979 peace treaty with Israel, Egypt has reduced its defense spending from 22 percent of its gross national product in 1974 to a mere 2.75 percent in 2002. Syria ‘s has fallen from 26 percent to 6.7 percent. The combined defense expenditures of Egypt , Syria , Jordan and Lebanon amount to only 58 percent of Israel ‘s. It is the Arabs who should be worried by Israel ‘s might, rather than the other way round.

Israel ‘s nuclear weapons are politically unusable and militarily irrelevant, given the real threats it faces. But they have been very effective in allowing India, Pakistan, Libya, South Africa, Brazil, Argentina, North Korea and now Iran to think that they, too, had good reason to build a nuclear deterrent.

Four of these nations have dismantled their nuclear arms factories, which shows that nuclear policies are not cast in stone. The way to deal with Iran is to prove to its leadership that nuclear weapons will add nothing to its security, just as they add nothing to Israel ‘s.

This may require a grand bargain, which would mean the United States offering a mutual nonaggression pact, ending its embargo over access to the International Monetary Fund and allowing American investment in Iran . It would also mean America coming clean about Israel ‘s nuclear armory and pressuring Israel to forgo its nuclear deterrent.

If Western powers want to grasp the nettle of nuclear proliferation, they need to take hold of the whole plant, not just one leaf.

Jonathan Power is a commentator on foreign affairs.

Originally published by the International Herald Tribune.