The American president claimed on Twitter that there would be new sanctions against Iran while Emmanuel Macron’s diplomatic adviser was in Tehran.

The French mediation in Iran was already difficult. Last week, Tehran claimed that Iran again breached commitments included in the nuclear deal. The day after the news broke, President Emmanuel Macron sent his diplomatic adviser to Tehran to work on deescalating the situation between the U.S. and the Islamic Republic. The purpose of the trip—try to convince the Iranians to correct their breaches of contract (excess stock over the 300-kilogram limit of enriched uranium and enrichment over the 3.67% degree limit) to avoid being sanctioned by the other countries involved—France, the UK, Germany, China and Russia—thus saving what is left of the Iran nuclear deal.

In exchange, after several discussions between the French president and his American and Iranian counterparts, France offered Tehran “intermediate measures” linked to the American sanctions on Iranian oil exports that are smothering its economy, likely the possibility for some countries to obtain exemptions from the U.S., allowing them to continue buying Iranian oil. This was without considering the unpredictability of a certain Donald Trump. Wednesday afternoon, while Emmanuel Macron’s diplomatic adviser was talking with the Iranian president, the American president indulged in a tweet proclaiming forthcoming “substantially” increased sanctions against Tehran.

A 259-Character Torpedoing

“Iran has long been secretly ‘enriching,’ in total violation of the terrible 150 Billion Dollar deal made by John Kerry and the Obama Administration,” tweeted the White House resident, referring to the Iranian nuclear deal he unilaterally pulled out of when Iran was indeed respecting all clauses, according to the International Atomic Energy Agency. The president threatened in the same message: “Sanctions will soon be increased, substantially!” In 259 characters, Donald Trump torpedoed French efforts to obtain a “break” in the crisis between Washington and Tehran, notably through an adjournment of some of America’s punitive measures.

“The Iranian President Hassan Rouhani did not fail to mention Donald Trump’s tweet to Macron’s adviser,” says a diplomatic source who was present. François Nicoullaud, former French ambassador to Iran, clarified, “If Donald Trump truly orders new sanctions, he will considerably irritate the Iranians, and French mediation will be over.” Surprisingly, a similar situation already happened a month ago, with the mediation attempt by Japanese Prime Minister Shinzo Abe in Tehran—even though it was preapproved by the American president. “Three days before his [Shinzo Abe’s] arrival in Iran, Donald Trump sanctioned the Iran petrochemical industry and ruined the negotiations,” recalled the former French diplomat.

What Leeway Does Macron Have?

“Donald Trump’s political communication does not show his true intent about Iran,” believes a source well-informed on the American-Iranian crisis. “The president is clear about one thing. He wants a good deal with Iran, produced by direct negotiations with Tehran, not the overthrow of the Islamic Republic.”

According to the Elysee, Donald Trump’s tweet did not affect French mediation in Tehran. “The French diplomatic adviser told the Iranians that discussions between Emmanuel Macron and Donald Trump make it possible to hope for a break in the escalation of the crisis,” says a diplomatic source. “And Iranians showed their interest in those discussions and are willing to continue to try to negotiate, especially now that many of their partners are abandoning the country.”

If the initiative is welcomed on the Iranian side, a lot of people question what leeway the French president really has when facing his unpredictable American ally and his “maximum pressure” strategy, aimed at getting Iran to kneel and agree to a global deal, over nuclear power, the missile program and Tehran’s regional “destabilizing” activities. “Americans won’t accept removing sanctions only to have Iran to go back on the nuclear deal,” predicts François Nicoullaud. “They will ask more than just respecting the nuclear deal.”

For now, France has set July 15* as a first deadline for Iran to decide on its offer. But the French position is especially delicate considering that France and the other countries involved in the Iranian deal could be required to sanction Iran themselves if it does not comply with the whole nuclear agreement.

*Editor’s note: Though this date is past, Watching America believes the content of the article is still relevant.