What happened?
On 16 April, Iran announced producing 60 per cent enriched uranium at its Natanz nuclear facility, two days after the IAEA said that Iran "had almost completed preparations to start producing UF6 enriched up to 60 per cent U-235".

On 15 April, talks resumed in Vienna between Iran, the US and European partners to salvage the 2015 Joint Comprehensive Plan of Action (JCPOA).

On 14 April, Iran's President Hassan Rouhani said that 60 per cent enrichment was a response to the alleged Israeli attack on the Natanz plant. France, Germany and the UK called it a "serious development" in a joint statement. The US called the move "provocative" while Saudi Arabia asked Iran to "avoid escalation" and "engage seriously in the current negotiations" in reference to talks happening in Vienna.

Earlier, on 11 April, Iran's Natanz enrichment facility suffered a power blackout, damaging the underground centrifuges. The "sabotage" was widely attributed to Israel, including by Iran's Foreign Minister, who called it an act of "nuclear terrorism".

What is the background?
First, Iran's position on enrichment. Iran has an ambiguous position on enrichment and nuclear weapons. While its official narrative claims that enrichment is not for weapons purposes, its actions say otherwise. Iran had a clandestine nuclear programme in the 1990s and early 2000s (suspended in 2003) despite being an NPT signatory. Post-2003, it has used the rate, quantity and percentage of enrichment both as a symbol of defiance and also as a bargaining chip, especially in the run-up to the JCPOA. Its current production of 60 per cent enriched uranium only takes it closer to the weapons-grade level and, contrary to its claims, is not for civilian purposes.

Second, Iran's nuclear capability. Iran primarily uses first-generation centrifuges (IR-1) at its Natanz enrichment site, even as it has also introduced new-generation centrifuges (IR-5 and IR-6). On 14 April, the IAEA said that Iran would be installing "six additional cascades of IR-1 centrifuges" at Natanz "comprising a total of 1,024 centrifuges". Iran is also developing advanced IR-9 centrifuges, which will be 50 times quicker than IR-1. Even though Iran is currently producing small quantities of 60 per cent enriched uranium, it can ramp it up.

Third, JCPOA and the contentious issue of enrichment. The JCPOA mandated that uranium could only be enriched up to 3.67 per cent and allowed this only at the Natanz enrichment facility with strict IAEA inspections. This was a significant takeaway for the US and the European partners of the JCPOA as this low enriched uranium cannot be used for strategic purposes. However, after former US President Trump withdrew from the JCPOA in 2018 and reimposed crippling sanctions (despite IAEA certified compliance), Iran responded by gradually breaching the nuclear deal. This includes surpassing the 300 kg limit on enriched uranium in May 2019 and enriching uranium up to 20 per cent in January 2021. Enriching uranium up to 60 per cent is the most significant breach of the deal so far. The question of enrichment is also central to the negotiations happening in Vienna currently. 

What does it mean?
First, Iran's move to enrich uranium up to 60 per cent is not a surprising one; it has gradually breached the nuclear deal since Trump's withdrawal in 2018. However, the sabotage at the Natanz facility has speeded up the jump from 20 per cent enrichment announced in January 2021 to 60 per cent now.

Second, 60 per cent enrichment has also brought Iran very close to the weapons-grade requirement of 90 per cent and will provide an upper hand to the country in the talks at Vienna. It has to be seen how Israel and Saudi Arabia, Iran's regional foes, respond to this. The possibility of another "sabotage" cannot be discounted at this stage.
Third, irrespective of the developments of the past one week, the talks at Vienna will continue. Instead, there will be more onus on the negotiators in Vienna now to find a peaceful way out of the nuclear quagmire.