The large number of attacks -- more than double the number in any of the past 25 years -- reflects a trend that has surprised and worried U.S. intelligence and military analysts.
More than four-fifths of the suicide bombings over that period have occurred in the past seven years, the data show. The bombings have spread to dozens of countries on five continents, killed more than 21,350 people and injured about 50,000 since 1983, when a landmark attack blew up the U.S. Embassy in Beirut.
Today is the 25-year anniversary of that attack, the first of a series of large suicide bombings targeting Americans overseas.
"Increasingly, we are seeing the globalization of suicide bombs, no longer confined to conflict zones but happening anywhere," said Mohammed Hafez of the Naval Postgraduate School in Monterey, Calif., and author of the book "Suicide Bombers in Iraq." He calls the contemporary perpetrators "martyrs without borders."
Deadly tactics from Argentina to Algeria
The unpublished data show that since 1983, bombers in more than 50 groups from Argentina to Algeria, Croatia to China, and India to Indonesia have adapted car bombs to make explosive belts, vests, toys, motorcycles, bikes, boats, backpacks and false-pregnancy stomachs.
Of 1,840 incidents in the past 25 years, more than 86 percent have occurred since 2001, and the highest annual numbers have occurred in the past four years. The sources who provided the data to The Washington Post asked that they not be identified because of the sensitivity of the tallies.
The data show more than 920 suicide bombings in Iraq and more than 260 in Afghanistan, including some that killed scores of U.S. troops. All occurred after the U.S. invasions of Afghanistan in 2001 and Iraq in 2003.
The exact number of U.S. casualties from the bombs in Iraq is classified "because it might show the effectiveness of the enemy's weapon," said Maj. Brad Leighton, a U.S. spokesman in Iraq. "They won't even give the number to me."
Beirut attacks caught U.S. by surprise
More than 3,420 Americans have died in at least 10 major suicide bombing incidents, beginning with the embassy bombing in Beirut, which killed 63 people, including 17 Americans, and injured more than 100. The bombing of the U.S. Marine barracks in Beirut six months later killed 241 and still ranks as the largest loss of American military life in a single incident since the Battle of Iwo Jima in World War II.
Both attacks caught Washington by surprise, despite suicide bombings against the Iraqi Embassy in Beirut in 1981 and an Israeli military headquarters in south Lebanon in 1983. "We at the embassy collectively saw the political situation as improving," said Richard Gannon, the regional security officer at the time.
The FBI and the CIA still do not know the identity of the bomber who, 25 years ago, drove a dark delivery van loaded with explosives past the red-and-white-striped security booth straight into the seven-story embassy overlooking the Mediterranean, ripping off the entire front facade.
Anne Dammarell, who worked for the U.S. Agency for International Development, vividly remembers being pinned under concrete with 19 broken bones, unable to move as flames approached. She said she decided to gulp smoke to "suffocate before being burned to death. I thought that would be easier."
The FBI eventually blamed a cell of Shiite extremists that later evolved into Hezbollah, and said Iran provided aid and direction. But few specifics are known to this day, and no one has been brought to justice, as in many such attacks.
'Legions of unknown soldiers'
At least two-thirds of suicide bombings since 1983 have targeted U.S. policy goals, intelligence officials say. "They may be targeting the U.S. but not hitting either the American homeland or American interests in other countries," said Gary LaFree, director of the University of Maryland's National Consortium for the Study of Terrorism and Responses to Terrorism.
Few of the perpetrators have been identified. "We're dependent on the terrorist group to make a public claim or release a martyrdom tape," said Bruce Hoffman of Georgetown University, author of "Inside Terrorism." "But if the bomber was never fingerprinted or governments do not have their DNA, he or she usually remains anonymous. What makes it so formidable a tactic or strategy is these legions of unknown soldiers deployed against us."
The State Department will hold a commemoration of the Beirut attack this morning.