WASHINGTON -- The warning from the White House to be on high alert this holiday season recognizes a tactic used by terrorists in the mountains of Peru, the back alleys of Belfast, the Middle East and Oklahoma City: Time attacks for maximum emotional impact.
Often that means an anniversary date or holiday.
Whether it's casting a pall over Christmas or forcing the public to remember an event that drove the terrorist to violence, datebook terrorism is about proving who controls the agenda, said Joan Deppa, a Syracuse University communications professor. "They're saying, 'I've got your attention, and by the way, if I can make your holiday miserable, all the better,"' she said.
Homeland Security Director Tom Ridge said the closeness this year of Christmas and Hanukkah to Eid al-Fitr, the joyous three-day feast that ends the holy month of Ramadan, could be tempting to terrorists who have a history of striking during religious observances.
"We do know that the next several weeks, which bring the final weeks of Ramadan and important religious observations in other faiths, have been times when terrorists have planned attacks in the past," he said.
Eid al-Fitr, fixed according to the sighting of the new moon and varying from country to country, falls around mid-December this year. Hanukkah, which began Sunday evening, runs through Dec. 17.
Ridge's warning stemmed from multiple, nonspecific threats for this period, but he made it clear that the calendar figured high in the government's concerns.
He cited the first World Trade Center attack in 1993, which fell during Ramadan, and foiled attacks planned around New Year's Day 2000, timed both for Ramadan and millennial celebrations. In recent years, Eid al-Fitr has been marked by violence in Indonesia in 1999, and in Bahrain, Egypt and Israel in 1996.
As familiar as datebook terror may be in the Middle East, it's not just Islamist militants who time their attacks.
Timothy McVeigh parked a truck bomb outside a federal building in Oklahoma City on April 19, 1995, and killed 168 people -- retribution, he said, for the deadly FBI raid on an encampment near Waco, Texas, exactly two years earlier. More than 80 people died then, people McVeigh considered martyrs to his anti-government creed.
In some countries, citizens could count on attacks according to the calendar. Until Peruvian authorities gutted the Shining Path in the early 1990s, the Maoist insurgency regularly staged car bombings and other attacks on the birthdays of founder Abimael Guzman on Dec. 3 and his idol, Mao Tse-tung on Dec. 26.
Before a 1997 truce, the history-obsessed Irish Republican Army would often stage attacks on dates marked by its followers but utterly obscure to others; for instance, Aug. 9, the anniversary of the introduction of internment without trial in Northern Ireland in 1971.