Washington - At first it seemed like just another of John Kerry's musings - Syria could stop threatened US military strikes by placing its chemical weapons stockpile under international control.
But within hours, as the US top diplomat was still in the air flying back to Washington from London, what appeared to be an off-the-cuff remark caught fire, with Russia embracing it and the Syrian regime also seemingly coming on board.
US President Barack Obama was due to take to the airwaves for a series of interviews later Monday to make the case for unleashing American firepower against the Syrian regime, which the US accuses of killing some 1 400 people in a sarin gas attack last month.
Political tensions are high with the first votes expected this week in Congress on whether to approve US military strikes against the Syrian regime.
So, in a war-weary world, perhaps it should be of little surprise that Kerry's idea gained swift traction.
In the slow-moving world of diplomacy however, where every remark is carefully calibrated and deliberated, it's rare to see ideas spread like wildfire.
And it remained unclear whether this was just another misstep by the gaffe-prone secretary of state, or a carefully choreographed plant, providing Obama with a possible exit strategy.
Kerry's predecessor Hillary Clinton, in an unusual appearance at the White House, also waded into the debate, saying it would be "an important step" if Syria's chemical weapons were surrendered to international control.
Asked early on Monday in London if there was anything Syrian President Bashar Assad could do to avert a US military strike, Kerry replied: "Sure."
"He could turn over every single bit of his chemical weapons to the international community in the next week. Turn it over, all of it, without delay, and allow a full and total accounting for that," Kerry told reporters.
Ran with it
He quickly seemed to shoot down his own idea, adding: "But he isn't about to do it, and it can't be done, obviously."
Except, Russian Foreign Minister Sergei Lavrov then took the ball and ran with in, calling on Damascus to "place the chemical weapons under international control and then have them destroyed."
Such a plan would help "avoid military strikes," Lavrov insisted, apparently after he had talked for 14 minutes with Kerry, who called him two hours after take-off from London.
During the call, Lavrov said he had heard Kerry's comments and Moscow would be willing to engage in the idea of an international supervision of Syria's chemical weapons stockpile.
Kerry however voiced serious scepticism saying the United States - now poised on the brink of ordering military strikes - was "not going to play games," a State Department official said.
If there was a serious proposal "we would take a look," Kerry reportedly added.
Moving fast before Kerry hit the ground again, Syrian Foreign Minister Walid al-Muallem in Moscow for talks "welcomed" the Russian initiative.
He said the scheme was "based on the Syrian leadership's concern about the lives of our nationals and the security of our country."
Britain's Prime Minister David Cameron - whose parliament voted against military action in Syria - was also quick to join in, saying it would be a "big step" if Assad were to hand over its chemical weapons.
And German Chancellor Angela Merkel said it was "an interesting proposal from Russia" adding she hoped "action would follow".
UN chief Ban Ki-moon also called for the creation of UN supervised zones in Syria where the country's chemical weapons could be destroyed.
Caught off-guard, State Department spokesperson Jen Psaki issued an email saying Kerry "was making a rhetorical argument about the impossibility and unlikelihood of Assad turning over chemical weapons he has denied he used".
Her deputy, Marie Harf, then insisted to journalists in an hour-long briefing that the idea was a Russian-Syrian plan not Kerry's.
"We'll look at this new development, we'll take a hard look at it," she said, but stressed: "Clearly, we don't want this... to be another stalling tactic."
Adding to the confusion however just moments later, Clinton said that "if the regime immediately surrendered its stockpiles to international control, as was suggested by Secretary Kerry and the Russians, that would be an important step."
During her four-year tenure as secretary of state, Clinton, who is weighing a run in the 2016 presidential elections, gained a reputation for weighing her words very carefully.