The leading compromise proposal is for the international community to endorse Iran's operation of a small research and development facility for enriching uranium. Iran would run an agreed number of centrifuges "less than 500 under the International Crisis Group plan released this week" while suspending fuller-scale applications of this technology until the International Atomic Energy Agency can resolve the serious doubts that Iran's nuclear activities have been and will be exclusively for peaceful purposes.

This is a bad idea, albeit the menu to choose from does not include any good options. (Endorsing enrichment in a country with Iran's still unresolved nuclear record and threatening international behavior would be unwise even if enrichment made economic sense; the fact that Iran has no need for homemade nuclear fuel makes the proposal even more suspect.)

Allowing Iran to operate a pilot-scale enrichment plant would give Iranian engineers all the opportunity they need to master this technology. Once this is done, Iran has jumped the major hurdle on the route to acquiring nuclear weapons.

Proponents of pilot-scale enrichment as the least-bad option assume that Iran does not or will not have secret facilities to conduct enrichment beyond the declared pilot facility that would be heavily monitored. Iran's failure after three years to give the IAEA an adequate explanation of what happened with the advanced centrifuge designs that Iran purchased on the black market indicates that, at least in the past, undeclared actors and facilities operated in the nuclear program. Still, proponents of the pilot-scale option argue plausibly that there is no proof that Iran now has secret facilities. Because Iran seems willing to create a major crisis and limit the International Atomic Energy Agency's inspectors if pilot-scale enrichment is not allowed, the hope is that giving Iran what it wants will motivate Tehran to allow intrusive inspections that will in turn deter any effort to use secret facilities to apply the knowledge gained in the pilot-scale plant.

Unfortunately, an internationally endorsed pilot-scale plant reduces the odds of detecting secret activities in several ways. If inspectors or spies detect suspicious procurement of parts or communications or other evidence related to enrichment, Iran can argue that the legitimate plant explains it. When no enrichment is allowed, any evidence is decisive; when some enrichment is allowed, all evidence may be ambiguous.

Iran's potential to break out of the nonproliferation treaty and move full speed to building nuclear weapons would grow greatly once it has mastered enrichment technology. Again, proponents of the pilot-scale fallback recognize this; they just think there is no better alternative.

But the pilot-scale alternative only postpones for a little while the hard dilemmas and dangers posed by Iran's nuclear ambitions. Iran has behaved according to a very clear logic since its major nonproliferation violations were detected in 2002. Indeed, Iran's chief nuclear negotiator from 2003 through 2005, Hasan Rowhani, has explained that Iran's strategy has been to suspend only those activities that it was not ready to undertake. Once the technologists have been prepared to take a new step in acquiring the capability to produce fissile materials, they have taken it and essentially dared the international community to stop them. This happened in 2004, in August 2005 with the re-starting of the uranium conversion facility at Isfahan, and in January 2006 with the end of suspension of uranium enrichment. In the Isfahan case, Iran crossed a redline established by the EU-3 and seems to have managed to erase it from the consciousness of many observers.

Iran's behavior and articulated strategy warn clearly that once it has mastered pilot-scale enrichment it will seek to do more, and will break any agreement to the contrary. A crisis, no less dire than the current one will emerge, only then Iran will be much closer to having the capability to make bomb fuel than it is today. There is no evidence that Iranian leaders are prepared to make a strategic decision not to acquire the capability to make nuclear weapons. The pilot-scale option enables Tehran to avoid this decision and proceed as it wishes.

Perhaps there is nothing the U.S. or others in the international community can do to persuade Iranian leaders to eschew their quest for dual-use facilities. But how would we know? The U.S. has not joined directly into the negotiating process with France, Germany and the United Kingdom, so Iran has not been able to factor its interests viz a vis the U.S. None of Iran's interlocutors, including the IAEA and its director general, has posed costs or benefits of sufficient magnitude and certainty to move Iranian decision-makers away from the path they are on.

Given the inadequacy of threats and inducements mustered thus far, many observers leap to the assumption that military attacks must be the alternative to acquiescence. Memories of the Bush Administration's run up to the Iraq war still loom large. When President Bush says banally (and unnecessarily) are not taking any option off the table, listeners leap to the conclusion that war is on. But discussions with a wide range of U.S. officials betray keen awareness that military attacks on Iran would probably result in a worse situation than we face today, and would not solve the strategic problem posed by Iran's nuclear ambitions and support of terrorist organizations.

Fixating on the shadow of military strikes is an excuse for avoiding the hard problem of mustering international unity to confront and persuade Iran to build a nuclear energy program that inherently reassures the international community that Iran will be a constructive, not a threatening, power on the world stage. This means unity in offering more positive incentives than Washington has contemplated, and more determined political and economic pressure than Russia, China, India and others have been willing to endorse. The volume of public warnings over the obvious dangers of military attack is so high compared to discussions of political-economic strategies that one detects an avoidance of responsibility for international stewardship.

To sharpen the point, imagine if President Bush unequivocally said that there is no military solution to the strategic challenge posed by Iran, and the U.S. will conduct no military operations against Iran unless Iran or its agents attack U.S. or friendly forces. Many would not believe such a declaration, which means there is nothing the U.S. can do in this regard, but if war is set aside does it make any sense now to open the door to uranium enrichment in Iran? Again, why is war being posed as the alternative to be avoided now? Why should Iranian decision-makers and public be spared from facing a higher set of costs in maintaining the current nuclear-weapon-option strategy? Why not hold the line at the critical point of uranium enrichment and offer Iran a higher set of benefits for switching to a nuclear energy policy that the world can live with?

Even leading organizations and individuals that incline toward the pilot-scale-enrichment 'compromise' recognize that it is undesirable. What is the imperative to fall back now? Doesn't it make more sense to seriously try the diplomacy of inducements and pressure by bringing the U.S. off the sidelines and directly into the multilateral negotiations with Iran?