In diplomatic negotiations, as in other contests, knowing more of your opponent's plans will help, but you still have to conduct the campaign. The revelation of a second enrichment plant in Iran will change some of the tactics of the six-nation group – the US, Russia, Germany, France, China and Britain – but their strategic goals remain difficult to achieve.
The goals are a high level of assurance that Iran will not divert nuclear material for military purposes and that it will take its place in its region as a constructive power. This requires a comprehensive agreement with Tehran and consequential moves on five tracks – in the International Atomic Energy Agency (IAEA), in the UN, and by Iran's main trading partners, the US, and Iran itself.
The centrepiece has to be an accord on Iran's nuclear programme. Either it suspends nuclear enrichment and conforms to its obligations under IAEA and UN security council resolutions, or an agreement acceptable to both bodies is reached on an alternative route to verifiable guarantees that its civil nuclear endeavours will not lead to a weapons capability, in accordance with the nuclear non-proliferation treaty.
What changed last week is that Iran has been put on the defensive – its protestations of purely peaceful intent look weaker than ever. The call for robust diplomacy is more credible to international public opinion. No one spoke out against hostility to Iran's behaviour at the UN last week, a fact already noted publicly in Tehran as a product of its current policy.
There is a better chance that Russia and China will agree to serious sanctions if Iran won't deal on the basis of the current proposal by the six-nation group and refuses to offer a plausible variant. There will be a better response from the EU, and maybe Iran's trading partners in the region. Not that sanctions are a panacea – they would take time to take effect, many of them could be evaded, and Iran can tighten its belt. But the risk to Iran of continued defiance has increased.
The best estimate of when Iran might get all the elements of a weapon system in place still appears to be that of Admiral Dennis Blair in his Annual Threat Assessment for the Senate of 10 March 2009: "We judge Iran probably would be technically capable of producing enough highly enriched uranium for a weapon sometime during the 2010-2015 time frame. [The state department bureau of intelligence and research] judges Iran is unlikely to achieve this capability before 2013 because of foreseeable technical and programmatic problems."
The problems referred to related in part to the setting up of a clandestine enrichment facility. Just such a plant – the newly discovered one – will now be monitored by the IAEA. But is there another, a Plan C? Does Iran already have the necessary clandestine plant for converting yellowcake to the gas that goes into centrifuges? Maybe, maybe not. In other words, there is both still some time to talk, and much urgency – and very high levels of distrust on both sides.
President Obama has called for immediate co-operation by Tehran. Despite the turmoil after the presidential election in June, the Iranian government remains in charge and is able to work on external as well as internal problems. It has the authority to negotiate and the power to make changes in its position, including making concessions, if it considers them necessary.
Even if Iran is prepared for serious talks on establishing its peaceful intentions, the 1 October meeting is likely to be only the start. Tehran has strongly expressed demands of its own. There will have to be points on the agenda for both sides, and steps taken to reduce Iranian distrust of its adversaries by discussing non-nuclear areas of dispute.