How many terrorist attacks have there been?

Answer 1

Nobody knows.

Terror attacks have been taking place for hundreds of years. From the crusades in Jerusalem, the Kamikazes in the second world war up to modern times.

Many terror attacks or attempted terror attacks aren't even officially recorded, due to national and global defence reasons.

Answer 2

2001 Sept. 11, New York City, Arlington, Va., and Shanksville, Pa.: hijackers crashed 2 commercial jets into twin towers of World Trade Center; 2 more hijacked jets were crashed into the Pentagon and a field in rural Pa. Total dead and missing numbered 2,9921: 2,749 in New York City, 184 at the Pentagon, 40 in Pa., and 19 hijackers. Islamic al-Qaeda terrorist group blamed.

2011 Jan. 17, Spokane, Washington: a pipe bomb is discovered along the route of the Martin Luther King, Jr. memorial march. The bomb, a "viable device" set up to spray marchers with shrapnel and to cause multiple casualties, is defused without any injuries.

Answer 3

172 terrorist attacks have been made since then