Two weeks ago, their idea was to hold an Iran-focused meeting in Poland and possibly outline the shape of a future "Arab-NATO" – a euphemism for an anti-Iran regional military amalgam.
But now, Poland might invite Iran to the international summit on February 13-14 and the US is saying the gathering is not at all aimed at "demonising" Iran.
So, what changed in a mere two weeks? And, is the summit going to be a dud?
Gulf state disputes
It started with the US State Department statement on January 11 announcing Washington will host a global conference in the Polish capital Warsaw, to discuss the Middle East, terrorism, and Iran in particular.
The announcement came in the middle of US Secretary of State Mike Pompeo's visit to nine Arab states, apparently to promote a US-backed plan to form what is being seen as "Arab NATO" that will pool armed forces from Arab states to counter threats from Tehran.
Iran quickly denounced the summit as America's anti-Iran "circus."
Then things started to unravel.
Pompeo's failure to end the stalemate between Qatar and its Gulf neighbours was the first setback.
Arab states Saudi Arabia, the United Arab Emirates, Egypt, Bahrain and Yemen, snapped ties and forced an economic blockade on Qatar in 2017 over Doha's alleged support for Muslim Brotherhood and ties with Iran.
Days before Pompeo's visit, the "unwillingness of the regional leaders" to end the dispute also frustrated US envoy Anthony Zinni so much that he resigned from the State Department.
In an interview with CBS News, the former Trump envoy tasked with resolving the Qatar dispute, also said there was no need for his role in introducing Gulf states to the idea of a Middle East Strategic Alliance – a NATO-style military coalition – since other members of the Trump administration [hinting at Mike Pompeo] are carrying it forward.
"Pompeo seems desperate to impose some kind of transformation in Iran – similar to what we see happening in Venezuela," Massoumeh Torfeh, a research associate at the London School of Economics and Political Science, told TRT World.
Torfeh, who is an Iran and Afghanistan expert, questioned the timing of the Warsaw summit.
"US National Security Adviser John Bolton says Iran will not celebrate the 40th anniversary of 1979 Islamic Revolution, and the Poland event is three days after the anniversary celebrations. February 14 also marks the day when Ayatollah Ruhollah Khomeini announced his fatwa against writer Salman Rushdie [February 14, 1989], so Pompeo is clearly planning to hype propaganda against Iran."
Iran nuclear deal
Relations between Iran and US are troubled, especially after the decision in May 2018 by US President Donald Trump to withdraw from a 2015 nuclear accord between Iran and world powers and to re-impose sanctions, including on Iran's oil sector.
The deal, signed in Austria by the US, France, Britain, Germany, China, Russia and Iran, removed sanctions in exchange for Tehran limiting its nuclear programme, designed to prevent the country from obtaining a nuclear bomb. Iran denies having nuclear ambitions.
Trump says the deal, signed during US President Barack Obama's tenure, failed to stop Iran's ballistic missile programme, its nuclear activities beyond 2025 or its role in the Yemen and Syria wars.
EU giants Britain, France and Germany, say abandoning the deal does not address US concerns and instead threatens stability in the Middle East.
On the Poland summit too, EU states seem reluctant to engage in activity that directly targets Iran.
Some EU diplomats are apprehensive the US choice of summit venue in Poland is aimed at driving a wedge between EU states over Iran.
This is perhaps why EU foreign-policy chief Federica Mogherini, who has led the EU efforts to sustain Iran nuclear deal, is skipping the summit.
Reportedly, the foreign minister of France is unlikely to attend the event. Other partners, like Britain and Germany, are undecided about their presence.
One European diplomat, quoted by The Wall Street Journal, said the European economic bloc would not be "joining an anti-Iran coalition".
Poland, US soften language
The snub has perhaps led to a change in plans with Poland's President Andrzej Duda saying it's still weighing the Iran invite, in contrast to earlier statements by Foreign Minister Jacek Czaputowicz justifying Iran's absence from the summit.
Iran's presence, he had said, would have undermined the talks because Tehran's language was "hard to accept."
The softening of Poland and the change of diplomatic language involved rushing Deputy Foreign Minister Maciej Lang to Tehran to clear up what Poland officials said were "misunderstandings about the Warsaw conference."
"For Poland, this conference is not against any country," Lang told AFP in an interview on Monday [January 21].
Iran had reacted angrily to the conference when news of it first broke.
Its Foreign Minister Mohammad Javad Zarif mocked the summit and pointed out that the country hosted more than 100,000 Polish refugees during World War II.
"Polish Govt can't wash the shame: while Iran saved Poles in WWII, it now hosts a desperate anti-Iran circus," Zarif tweeted on January 11.
A diplomatic victory for Iran?
Poland's tactical U-turn was followed by the US deputy ambassador to the UN Jonathan Cohen's assurance on Tuesday [January 22] that the conference in Warsaw is not aimed to "re-litigate the merits of the JCPOA [the 2015 Iran nuclear deal]."
"It is also not a venue to demonise or attack Iran," Cohen said.
With around three weeks to the Warsaw summit, Iran may have struck a diplomatic victory over the US.
"... Trump administration has already backtracked from Pompeo's original framework for this summit, shifting from an anti-Iran discussion to a broader Middle East security. However, the fact that Iran has been excluded from the meeting, and that the US Iran Action Group is reportedly in charge of coordinating the summit, signals that the agenda will have a heavy Iran focus," Ellie Geranmayeh, a senior policy fellow for the MENA Programme at the think-tank European Council on Foreign Relations argues.
"If the summit ultimately fails it may serve Tehran's interest not to over-react and instead point to this as another failed attempt by Washington to turn the world against Iran," she observed.