By Kristian Alexander

The September 11, 2001, attacks highlighted significant US vulnerabilities and led to major counterterrorism reforms. Post-9/11, the US government implemented institutional changes, enhanced international cooperation, and expanded its use of technology and drone warfare. However, public fatigue from prolonged wars and shifting US focus towards geopolitical rivalries and domestic issues has reduced the centrality of counterterrorism in US policy over the last two decades. COMMENTARY The terrorist attacks of September 11, 2001, remain one of the most devastating strategic surprises in modern history. Despite being the world’s preeminent superpower with an extensive intelligence apparatus, the United States failed to anticipate and prevent the hijacking and subsequent crashing of four commercial airliners, killing almost 3,000 people.

Singapore: The S. Rajaratnam School of International Studies (RSIS) , 2024. 4p.

By Ahmet Gule and Mustafa Demir

This study examined the effectiveness of post-9/11 U.S. counterterrorism policies in preventing terror attacks and reducing casualties against American targets within and outside the United States. Monthly data on terrorism incidents from July 1981 through December 2020 were obtained from the Global Terrorism Database (N = 462). The results of monthly interrupted time-series analyses showed that within the United States, after the 9/11 attacks, the number of attacks, the number of successful attacks, and the successful attack rate statistically significantly decreased in the first month following 9/11; then, no significant increase was observed in the trend of those outcomes. Outside the United States, after the 9/11 attacks, the trend of the number of successful attacks, the number of victims, the number of nonfatal victims, and the victim rate statistically significantly decreased. The results suggest that post-9/11 U.S. counterterrorism policies are effective both domestically and internationally. These findings and their policy implications are discussed.

Criminal Justice Policy Review OnlineFirst, Sept. 2024