When someone pulls a rabbit out of a hat, it's natural to be suspicious. Magicians are professionals in deceit - and so are diplomats. But sometimes the rabbit is real.
On Monday morning, the world was heading into the biggest crisis in years: a looming American attack on Syria, a Russian response that could set off the first major confrontation between Washington and Moscow since the Cold War, and the possible spread of the fighting from Syria to neighbouring countries. Or alternatively, a congressional rejection of President Barack Obama's plans that would have left him a lame duck for the next three years.
By Tuesday morning all that had changed. A Russian proposal for Syria to get rid of all its chemical weapons was promptly accepted by the Syrian Foreign Minister, Walid al-Moallem, and the Senate vote on Mr Obama's planned strikes on Syria was postponed, probably for weeks. If Syria keeps its word, the vote may never be held. What a difference a day makes.
At the Moscow G20 summit last week, Mr Obama and Russian President Vladimir Putin had a chat at which one of them broached the possibility of persuading Syria to give up its chemical weapons entirely. Which one isn't clear, and the idea was not pursued by either of them.
Yet both had reason to want such a thing, for the alternative was that Mr Obama would lead the United States into another Middle Eastern war, or that he would not get congressional approval to do so and end up completely discredited. Mr Putin would feel obliged to respond to a US attack on his Syrian ally, but that could end up with Russian missiles shooting down American planes.
On Monday, John Kerry, the US Secretary of State, gave an off-the-cuff reply to a question about whether Syria's President Bashar al-Assad could avoid an American attack. "Sure. He could turn over every bit of his [chemical] weapons to the international community within the next week, without delay," said Mr Kerry with a shrug. "But he isn't about to."
Then Mr Kerry got on a plane to fly home, and halfway across the Atlantic he got a call from Russian Foreign Minister Sergei Lavrov saying that he was about to announce that Russia would ask Syria to put all its chemical weapons storage facilities under international control, join the Organisation for the Prohibition of Chemical Weapons, and destroy them all.
The Syrian Foreign Minister happened to be in Moscow, so within an hour he declared that Mr Assad's regime "welcomes Russia's initiative, based on the Syrian Government's care about the lives of our people and security of our country". By Monday evening Mr Obama was saying the Russian plan "could potentially be a significant breakthrough", and the pot was off the boil.
The whole thing, therefore, was made up on the fly. That doesn't necessarily mean that it won't work, but it is a proposal that comes without any of the usual preparation that precedes a major diplomatic initiative.
There is a great deal of suspicion in Washington that this is merely a delaying tactic meant to stall an American attack and sap the already weak popular support in the United States for military action. Moreover, it will be hard to send international troops in to secure Syria's chemical weapons unless there is a ceasefire in the civil war.
But the American military will be pleased, because they were unhappy about the job that Mr Obama was giving them, and Mr Obama looks like a man who has been granted a new lease of life.
• Gwynne Dyer is an independent journalist whose articles are published in 45 countries.