Counterterrorism forces expanded with the perceived growing threat of terrorism in the late 20th century . Specifically , after the September 11 attacks , Western governments made counter-terrorism efforts a priority , including more foreign cooperation , shifting tactics involving red teams and preventive measures . Although sensational attacks in the developed world receive a great deal of media attention , most terrorism occurs in less developed countries . Government responses to terrorism in some cases generate substantial unintended consequences
September 11 attacks
September 11 attacks
Counter-terrorism