My Notion of Terrorism

"Terrorism" is practically the most frequently used word now. People are scared. Nearly every accident is claimed to be an act of terrorism. But what is terrorism? What people can be called terrorists?
August 1945: the United States Air Force drops the
world's first nuclear weapons.
September 2002 - the attack on Twin Towers and the Pentagon.
October 2003 - hostages in the musical "Nord Ost".
December 2002 - February 2003 - the USA is getting ready to bomb Iraq .
Which of these four events was an act of terrorism? Which achieved or will achieve anything? …