Terrorism and violent extremism pose serious and changing threats to global peace, security, human rights, and long-term development. Victims, families, and communities suffer immeasurable pain as a result of these threats. While countering terrorism poses substantial obstacles for states and other organizations, it is critical that all national counter-terrorism measures comply with legal and human rights norms. This is critical for maintaining public authorities’ confidence and legitimacy, as well as preventing further radicalization that leads to violence. The 9/11 incident is widely regarded as one of the most serious terrorist actions of the twenty-first century. against September 11, 2001, 19 militants affiliated with the Islamic extremist organisation al Qaeda hijacked four planes and carried out suicide assaults against US targets. Two planes collided with the World Trade Center twin towers in New York City, a third jet collided with the Pentagon outside Washington, D.C., and a fourth plane crashed in Shanksville, Pennsylvania. The 9/11 attacks killed approximately 3,000 people and triggered substantial US attempts to combat terrorism and violent extremism across the world. Numerous such assaults have happened since then as a result of the broad and complicated network of terrorist groups that continue to constitute a substantial danger, undermining worldwide peace and cooperation.