It is proving a messy week in the attempt to curb Iran’s nuclear ambitions. In the battle of rhetoric, Iran has even managed to emerge as the moderate voice.

Yesterday President Ahmadinejad said that comments by two French ministers about the rising risk of war with Iran were intended for the media and should not be taken seriously. “The remarks made to the press are different from genuine statements, so we do not consider these threats to be serious,” he said – as it happens, in remarks to Iranian reporters, although he presumably did not intend the same dictum to apply to himself.

Three factors have changed in the past month to fan the heat. First, Mohamed ElBaradei, Director-General of the International Atomic Energy Agency, the United Nations nuclear watchdog, has provoked fury among the countries trying hardest to put pressure on Iran – the US, Britain, France and Germany – by offering Iran a deal of his own devising. Without consulting these countries, in late August he offered Iran a bargain: it would answer puzzles about its 20-year covert programme and, in return, he would not demand that it suspend enrichment of uranium, the most controversial technique.

The Western countries accused him of destroying four years of diplomacy out of his own desire to indulge Iran and his antipathy to the US. Some think that the award of the 2005 Nobel Peace Prize went to his head, encouraging him to forge his own path rather than merely inspecting facilities to judge compliance with the Nuclear NonProliferation Treaty (NPT).

They have a point. Under the NPT, Iran is obliged to explain its programme. It is also not allowed to pursue enrichment if there is cause to think that this supports an illicit weapons programme, as the West suspects, although Iran denies it.

To try to regain the upper hand, the US has called a meeting of the political directors of the five permanent members of the UN Security Council – the US, Britain, France, China and Russia – plus Germany, in Washington on Friday.

The second factor that has turned up the heat is France’s willingness, under its new President, Nicolas Sarkozy, to take a more aggressive line. It has called for more sanctions on Iran and asked big French companies not to invest there. Even though Jacques Chirac, Sarkozy’s predecessor as president, backed the notion of putting increasing pressure on Tehran, his opposition to the US invasion of Iraq, and the resulting frost, weakened the alliance. At the weekend, in the comments that provoked Ahmadinejad, Bernard Kouchner, the French Foreign Minister, said that Paris should prepare for the chance of war with Iran although he did not think that any was imminent.

The third provocation is a split within the White House about how aggressively to confront Iran. In last week’s Iraq debates, President Bush began to describe that conflict as a way of countering the influence of Iran in the region. Dick Cheney, the Vice-President, leads the more hawkish wing, which the President’s remarks appeared to reflect. Condoleezza Rice, the Secretary of State, in a rare departure from Bush’s line, is said firmly to favour the diplomatic route, albeit with tougher sanctions.

That division makes it hard to predict what the US might do, but meanwhile it injects the language of war into the debate. Friday’s meeting will help to show whether diplomacy and sanctions can regain their lost momentum.

Times Recommends

• The ghost of Robin Cook haunts Chilcot’s feast
• The truth shouldn’t need oaths
• Violence: let’s separate the men from the boys