W.r.t Iranian bomb, It is not simple matter of bringing enrichment from the 80% "hold" currently done in its stockpile and centrifuge series to say 90%+ (for a bomb). There is the significant extra step of then changing the cooled HEU hexafluoride to uranium metal again and then processing of the HEU metal into a bomb.
i.e way too many people assume the leap from 80% to 90% is the final piece of the puzzle, it is not.
The issue with Iran's nuclear bomb production realization is thus hampered severely due to IAEA regime it is under, combined with the uranium (i.e HEU gas centrifuge) route elected for (this was the only expedient option on the AQ Khan tech transfer):
- Iran is an NPT signatory, i.e subscribes to IAEA safeguard program and inspection.
- There are significant signatures that would become apparent to IAEA inspectors (and others remotely sensing even) regarding hexafluoride -> metal -> bomb material
- The significant RnD involved in these final stages and detection signatures for those too. i.e example what China provided Pakistan in the 80's (direct materials involved).
- The logistical penalties of trying to move the bomb production away from UF6 production area ( like Saddam Hussein tried to continue for a longer term capability retention after Osirak was destroyed, that was detected and forms basis of many of these signatures IAEA et al monitors now). There is reason countries with nuclear bomb capability, using the Uf6 gas centrifuge route, keep these concentrated in one location. There has been no alarming remote sensing of the expansions needed in Iran's facilities.
- i.e we would be hearing about this for a few years already if something taking place in the final crucial stages.
So afif and others are correct its very unlikely.
Another short summary: