On May 3 the representatives of 188 nations (give or take a few) will assemble in New York City to debate ways to revise the Nuclear Non-Proliferation Treaty. The issue could not be more important. As President Obama's new Nuclear Posture Review declares, the greatest threats to global security are not the old Cold War adversaries but rogue states armed with nukes and terrorists with access to such bombs or the materials from which they can be made. Moreover, the NPT is severely challenged by Iran, which, the IAEA has repeatedly reported, is not living up to its obligations under the treaty. Other nations with nuclear ambitions are watching to see how the international community will react to Iran's violations, as they figure out their own military futures.

If one examines previous meetings of the NPT signatories, one does not find them very reassuring, to put it mildly. During the last meeting of this group--which includes representatives of most nations of the world--those present debated the agenda for two weeks, and then went home.

This time the meeting is viewed with special interest because President Obama is seeking to garner support from many nations that in the past were very critical of the U.S. and other nations that already have nukes for not living up to their commitment under the NPT, namely to give up their nukes. President Obama thus declared that indeed zero nukes is the goal, and showed that he means business by working out a treaty with Russia that would scale back the number deployed on the top of launchers. He also obtained a measure of new support from a recent meeting of 47 nations in Washington, to better secure the remaining nukes and blend down the materials from which they can be made.

How is one to assess the achievements of the forthcoming NPT conference? I predict that much attention will be focused on the posturing of various nations (Iran is a member), criticisms of the members of the nuclear club (who still have enough nukes to kill most everyone three times over) and the nations that did not join the NPT (Pakistan, India, and Israel). Possibly some progress will be made in passing a resolution that urges the member nations to endorse the so-called "Additional Protocol," which widens the scope of IAEA inspections. However, the true test of the 2010 NPT conference lies elsewhere.

The NPT has one major, debilitating flaw. It has a loophole so large that aircraft carries can sail through it unnoticed. The NPT allows a nation to build nuclear reactors using highly enriched uranium, which is weapons-grade material, as well as to build the facilities needed to enrich additional uranium to this level--as long as the nation claims that these materials are to be used for peaceful purposes. The nation is then entitled to send a notice that it is quitting the treaty and three months later do so, taking with it all these facilities, and legally begin making bombs. A nation hence need not cheat, hide its bomb making from inspectors, or face criticism and possible UN sanctions. All it takes is basically a postcard.

Thus when one evaluates whether the NPT review conference is truly succeeding, or mainly dealing with atmospherics and debating points and possibly some secondary issue, ask whether this loophole is closed. My expectation? Do not hold your breath, lest you turn very blue.