And to think, I was worried I wouldn’t be able to find a hook for this piece.

It was a snap inspection, says the UN, so they suspect what they saw accurately reflects what Iran’s been doing day to day. With only two hours’ notice, the technicians simply wouldn’t have had time to put a dog and pony show together.

Verdict? Not so good.

Inspectors for the International Atomic Energy Agency have concluded that Iran appears to have solved most of its technological problems and is now beginning to enrich uranium on a far larger scale than before, according to the agency’s top officials…

Until recently, the Iranians were having difficulty keeping the delicate centrifuges spinning at the tremendous speeds necessary to make nuclear fuel and were often running them empty or not at all.

Now, those roadblocks appear to have been surmounted. “We believe they pretty much have the knowledge about how to enrich,” said Mohammed ElBaradei, the director general of the energy agency, who clashed with the Bush administration four years ago when he declared that there was no evidence that Iraq had resumed its nuclear program. “From now on, it is simply a question of perfecting that knowledge. People will not like to hear it, but that’s a fact.”

The qualifiers fly fast and furious after that: setbacks in the enrichment process are common, the uranium would need to be further enriched for four or five months before it was weapons grade, and even if they did build a bomb, they’d have to figure out how to miniaturize it before it would fit in a warhead — assuming, that is, they don’t have some other delivery system in mind. (The Times notes that a document found in Iran’s possession last year shows a sphere-collision process the only known application of which is in a nuclear weapon, a fact previously reported but often overlooked.) It’s worth revisiting a post written last month by arms control expert Jeffrey Lewis, though, to see what he considered to be the major stumbling blocks in Iran’s program. Namely:

1. In order to build a bomb, Iran needs to run its centrifuges continuously. At the time of Lewis’s post, the best evidence was that the machines were running only 20% of the time.
2. The more centrifuges Iran is operating, the faster it can build a bomb. Lewis suspected that the 1,000 centrifuges then in operation had been purchased wholesale from A.Q. Khan’s black market, as there was no evidence that Iran was capable of mass producing its own components. To add more, they’d either have to find another dealer or build their own.

The fact that the machines were both on and filled with uranium when the inspectors came knocking suggests at the very least that they’ve gotten closer on point 1. How much closer will be a point of fierce debate, I’m sure. But what about point 2? Back to the Times:

According to diplomats familiar with the inspectors’ report, in addition to 1,300 working centrifuges, another 300 were being tested and appeared ready to be fed raw nuclear fuel as soon as late this week, the diplomats said. Another 300 are under construction.

“They are at the stage where they are doing one cascade a week,” said one diplomat familiar with the analysis of Iran’s activities, who declined to be identified because of the sensitivity of the information. A “cascade” has 164 centrifuges, and experts say that at this pace, Iran could have 3,000 centrifuges operating by June — enough to make one bomb’s worth of material every year. Tehran may, the diplomat said, be able to build an additional 5,000 centrifuges by the end of the year, for a total of 8,000.

And if they can’t build ’em, they might indeed be able to buy ’em, A.Q. Khan’s retirement notwithstanding.

The upshot of all this, as the Times explains, is that sanctions as a means of prevention may have already failed:

“Quite clearly, suspension is a requirement by the Security Council and I would hope the Iranians would listen to the world community,” [ElBaradei] said. “But from a proliferation perspective, the fact of the matter is that one of the purposes of suspension — keeping them from getting the knowledge — has been overtaken by events. The focus now should be to stop them from going to industrial scale production, to allow us to do a full-court-press inspection and to be sure they remain inside the treaty.”

In other words, the focus might have to shift now from stopping them from building a bomb to slowing them down by limiting the number of centrifuges. So much for preventative sanctions. Sanctions as a punitive measure — to squeeze the country so hard economically that the people might challenge the regime out of desperation — are of course still possible, but how likely is it that they’d work well enough to topple the mullahs before they had a bomb in hand?

A quick check of Jeffrey Lewis’s blog reveals that he hasn’t commented yet, but Danger Room has. And the most encouraging words Noah Shachtman can muster is that we do need to do something about this soon — just not right this second. Whew!