Western governments' attempts to halt Iran's nuclear program are often rebuked rhetorically by the argument of "double standards." Without forcing Israel to denuclearize, the argument goes, the West has no right to deny Iran the right to an atom bomb.

But on the international system differing standards exist everywhere--not all regimes are created equal. It's also not clear why Iran's denuclearization should be morally based on Israel's (opposed to Pakistan's, or even America's for that matter) denuclearization.

Nevertheless, the important point is that the ideal world is one without nuclear weapons. In the real world, a minority of countries have nukes. As that number increases, the chances of nuclear weapons falling into the wrong hands increases exponentially. The collective moral goal must be to stop this at all costs--lest we want to face a future of nuclear terrorism.

Thus, a universal standard for nuclear weapons is similar to Hammurabi's famous eye-for-an-eye penal code. On an individual level, it is certainly the most equitable--nothing is more fair. But on a collective level everyone goes blind.