Vienna, the capital of Austria, has historically hosted many a key diplomatic event. The famous Congress of Vienna, held in 1814-15, reconstituted the European political order after the fall of Napoleon. In a myriad ways, thereafter, the city became the hub of peace diplomacy. Today the United Nations has housed one of its headquarters there, the International Atomic Energy Agency, the global nuclear watchdog seeking to promote the peaceful use of the power of atom and inhibiting its military application.

Small wonder this was the chosen site for reaching the Joint Comprehensive Plan of Action (JCPOA)in 2015 between Iran and six other nations-China, France, Germany, Russia, the United Kingdom and the United States seeking to curb the former's alleged nuclear ambitions. In return, crippling sanctions on Iran, imposed earlier to discourage a perceived plan to weaponize its nuclear resources, were to be lifted. But the pact became threatened when President Donald Trump pulled the US out of it in 2018. The decision of the current Biden administration to re-engage with the deal is witnessing this week a return to resumption talks in this fair city; albeit very indirectly and very circumspectly.

The JCPOA came after years of tension over Iran's nuclear programme. Iran had insisted it was entirely peaceful, but some key members of the Security Council thought otherwise. They believed Iran had large stockpiles of enriched uranium and almost 20,000 centrifuges seen to be sufficient fissile material to create 8 to ten atom bombs. Indeed, some of their analysts calculated that the "break-out" time for nuclear weaponization was estimable at 2 to 3 months. The UN, the US and the European Union aiming to force Iran to halt uranium enrichment, imposed severe sanctions that cost the country around US $ 160 billion in oil revenues from 2012 to 2016.

The Obama administration then joined the UK, France, Germany, and also having roped in China persuaded Iran to come to an understanding, the JCPOA, that was seen as satisfying to all parties. Under the accord Iran agreed to some key steps in return for the removal of the sanctions. Earlier, in Iran's two facilities, at Natanz and Fordo, uranium hexafluoride gas was fed into centrifuges to separate out the most fissile isotope U 235. Though the enrichment was a far cry from the 90 percent needed for bombs, Iran agreed to cap it to 3.67 percent. It also consented to limit itself to installing no more than 5060 centrifuges and reducing its stockpile by 98 percent to 300 Kg. Furthermore, Iran committed to "an extraordinary and robust monitoring verification and inspection".

Iran began its compliance procedures, reduced numbers where necessary and shipped off tons of low-grade enriched uranium to Russia. Sanctions were being lifted. Iran gained access to more than US $ 100 billion worth of assets frozen overseas. Sale of oil on international market by Iran was resumed. Then the process received a severe jolt with the arrival on the scene of Donald Trump. Egged on by Israel, Trump, much like Oliver Twist, wanted more. He assessed that further concessions from Iran could be forthcoming if this deal is scuttled and another negotiated under tighter sanctions. That could also be crafted to include ballistic missiles, outside the scope of the current one. Though there was absolutely no proof that Iran was in default, Trump "snapped back" sanctions to the dismay of other treaty partners.

The European Union urged Iran to continue to comply, though that was by now less than reasonable. Still, Iran did so for a year to flag its commitment to the JCPOA and then, understandably began to enrich its uranium. At the same time, Iran turned towards China, and completed the negotiations for a bilateral deal with massive implications. On 22 March Iran and China signed a 25-year cooperation programme, which was also called a ''Comprehensive Strategic Partnership". Though details are still pending, it is said to entail Chinese investments in Iran to the tune of US $280 billion for developing Iran's oil, gas, and petrochemical sectors and US $ 120 billion for upgrading Iranian transport and manufacturing sectors. In return, Iran would supply China oil for its energy -hungry economy, heavily discounted. This agreement would now not only buttress Iran's negotiating clout in the context of the JCPOA, but would also shore up both its economy, relieving somewhat the stresses of sanctions. At the same time because it is called "strategic", it would shore up Iran's security and defence sectors. The upshot is, Iran returns to Vienna, more empowered.

The on-going negotiations are complicated, both in terms of format and content. The key protagonists, the US and Iran would not interface directly, but only via the other JCPOA powers, with the European Union chairing the conference. In the opening rounds, both the US and Iran are asking the other side to make the first move. Ultimately it will need to calibrate a choreography for a "compliance for compliance" understanding. In the meantime, an explosion at Iran's Natanz nuclear facility that knocked off power-supply has been blamed on Israel by Iran. The Iranian Foreign Minister Javad Zareef has vowed that as a retaliatory consequence, Iran would triple its enrichment of uranium from 20 percent to 60 percent, bringing it much closer to weapons-grade. This incident has exacerbated the complications, though it is too soon to assess its impact on the Vienna negotiations. The talks will, therefore, resemble a very slow waltz in Vienna, but could bring joy to the dancers if they can calibrate their steps carefully to the tune of peace.

Dr Iftekhar Ahmed Chowdhury is the Honorary Fellow at the Institute of South Asia Studies, NUS. He is a former Foreign Advisor (Foreign Minister) of Bangladesh and President and Distinguished Fellow of Cosmos Foundation. The views addressed in the article are his own. He can be reached at: isasiac @nus.edu.sg