Islamic anger over the publication of cartoons depicting images of the Prophet Mohammed caused riots throughout the world in January and February, with some Muslim protesters in London holding up banners urging people to "Behead those that insult Islam." Pope Benedict XVI's Sept. 12 comments that seemed to equate Islam with violence also caused outrage and mass protests.
And there were the daily images of carnage in Iraq, Israel's bloody war with Hezbollah guerrillas in Lebanon, and the continued controversy over the US detention facility at Guantanamo Bay, Cuba.
A senior French counterterrorism official said intelligence agencies throughout the continent are on "tenterhooks" and that "all of the warning lights are red," though they have not uncovered any specific plan for an attack.
"The threat is at its highest level," said the French official, who spoke on the condition of anonymity because of the secretive nature of his job. "All [security] services are on tenterhooks. And it's not just us [in France]. Work is underway everywhere, but nothing concrete is emerging.
"Ends of the year are often bad. This year we haven't managed to distinguish a precise plot."
Those fears were echoed in Britain, already on edge after the failed August plot to bring down commercial jetliners over the Atlantic.
John Reid, Britain's top law enforcement official, said Sunday that it was "highly likely" that terrorists would attempt an attack over the holiday period. He gave no other details.
