US ambassador Howard Leach is based in the heart of Paris
Even before the US suicide-hijackings, French officials were investigating reports of a plot to blow up the US embassy in Paris.
The inquiry began just one day before the 11 September attacks.
Now, suspected militant Djamel Beghal has reportedly confirmed to French investigators that a suicide bomb attack was being planned - and that Osama Bin Laden was behind it.
As more details of the planned attack emerge, it appears that the militants were targeting a US cultural centre in Paris as well as the embassy itself.
Both attacks would have brought carnage and chaos to central Paris.
Unlike the spectacular synchronised method used in the US, the French plot was a much cruder affair.
Suicide bomber
Mr Beghal has reportedly named a Tunisian arrested in Belgium as the chosen suicide bomber.
His task was to enter the US embassy, just off the Place de la Concorde, with explosives strapped to his body, and blow himself up.
A van packed with explosives would have been driven separately to the US cultural centre, also in the heart of Paris, and detonated.
The timing of the attack has not been revealed. There has been no hint that it was being planned to coincide with the devastating attacks in the US.
Vigilance
US embassies have been targeted in the past by extremists linked to Osama Bin Laden.
The most deadly attacks came in Kenya and Tanzania in 1998, when more than 200 people died as trucks filled with explosives were rammed into the buildings.
Mr Beghal is believed to have given key information to investigators in Dubai, where he was detained in July - but it is not clear what prompted the French inquiry itself to begin just one day before the US attacks.
He was only arrested because of the vigilance of Dubai officials, who noticed that he was travelling on a false passport.