Iran analyst Patrick Disney examines why it might be a US or Israeli red line for Iran to install advanced centrifuges at the Fordow facility and explains why the US will continue pushing Iran to relinquish its stockpile of 20% enriched material at the next round of P5+1 nuclear negotiations:

If you recall, Matthew Kroenig and Colin Kahl, both recently-departed Obama administration officials, noted that if Iran were to install advanced centrifuge designs in the deeply-buried Fordow facility, then Western officials would need to consider taking military action against that site.  Kroenig said such a move by Iran would mean “the United States must strike immediately or forfeit its last opportunity to prevent Iran from joining the nuclear club.”

I viewed this as an unreasonable redline to draw, since Iran is already operating next-generation centrifuges at its other enrichment facility and that moving IR-2m or IR-4 machines into Fordow wouldn’t fundamentally alter the nature of Iran’s nuclear weapons potential in the same way that, say, a decision to start stockpiling weapons-grade uranium would.  But I then got to thinking: wouldn’t more advanced centrifuges at the Qom site mean Iran could breakout quicker — possibly even in the 2-3 months between IAEA inspections?  That would, after all, fundamentally alter the state of play on the nuclear issue, and probably would necessitate some deep thinking in Washington and Tel Aviv.

So let’s figure out what we’re really dealing with here.

Read on.