Q+A: Is Iran nearing nuclear "breakout" ability?

(Compiler's note: Would someone please rephrase the question? Read the answers closely and draw your own conclusion.)

Admiral Mike Mullen, head of the U.S. military Joint Chiefs of Staff, said he believed Iran has enough material to make a nuclear bomb, but Defense Secretary Robert Gates said Tehran was not close to having such a weapon.

.... IS IRAN ON THE VERGE OF BOMB STATUS?

No, unless it has secret enrichment facilities and there are no known indications of that. Otherwise Iran would have to overcome a succession of technical challenges, though none as hard as producing quality nuclear fuel in industrial quantities.

These include:

* reconfiguring its existing centrifuge enrichment plant at Natanz to reprocess LEU into weapons-grade HEU, or building clandestine facilities without the knowledge of U.N. inspectors

* converting HEU into metal and compressing it small enough to fit into the cone of a missile or other delivery vehicle

* designing a nuclear trigger mechanism

* mastering how to create a sustained nuclear chain reaction with an extra source of neutrons

* assembling the actual warhead, and a reliable means of delivery -- probably a missile

All this could take 2-5 years, depending on Iran's technical prowess, but probably much less time than the 20 years it took Iran to acquire enrichment equipment and knowledge from the nuclear black market and make it work.

ARE THERE OTHER RESTRAINING FACTORS?

Yes. It would be virtually impossible for Iran to "weaponize" the enrichment process at Natanz without the IAEA noticing and sounding the alarm, since the plant is under regular surveillance by inspectors.

Iran has pledged to stick to enrichment for civilian energy only, under routine IAEA monitoring. It has said nuclear weapons are against its Islamic values although its record of nuclear secrecy and limiting IAEA access has raised suspicions.

Assuming Iran had a bomb agenda, which it denies, military diversions would more likely be carried out at a covert plant. That would be almost inconceivable for the IAEA to ferret out since Iran does not observe the agency's Additional Protocol allowing snap inspections beyond declared nuclear sites.

If Iran chose to weaponize enrichment at Natanz, it would probably kick out the IAEA and quit the Non-Proliferation Treaty, drastic steps that would almost certainly provoke Israeli or U.S. attacks to destroy its nuclear facilities.

ARE ENRICHMENT AND A BOMB AGENDA THE SAME THING?

No, but it's not so simple. Iran says it will not refine uranium for anything else but electricity. Being able to enrich at industrial scale is not tantamount to seeking a nuclear weapon and is the sovereign right of NPT members as long as the work remains strictly for peaceful applications.

But the dilemma is that mastering enrichment technology provides a latent ability to build bombs in the near future. That may be all that Iran is seeking, as the ultimate deterrent against attack and a means to assert its regional power, and there is nothing illegal about having such capability.

Dozens of countries have such "breakout" capability, but do not exercise it as NPT members. The distinction between latent capacity and deionization can be virtually invisible in a vast country that limits the scope for U.N. non-proliferation inspections.