Terrorism is on the decline now – effective counter measures.
New America N.D (New America is a think tank of police experts and intellectuals that seek ton find problems to social and technological changes in America. Terrorism in America 18 Years after 9/11: What is the Threat to the United States.) https://www.newamerica.org/international-security/reports/terrorism-america-18-years-after-911/introduction
The number of cases of individuals being charged with terrorism-related crimes has dramatically decreased since 2015 when it was at its peak with 80 cases. This trend of decline is almost certain to reverse this year with a slight uptick in charges. There have been 19 cases as of September 11, 2019, compared to 19 cases over the whole year in 2018. Policymakers should be wary of reading too much into the number of prosecutions. There may be cases that are not yet public but were charged in 2018, and the number of prosecutions can reflect prosecutorial decisions regarding how aggressive to be or the wrapping up of investigations where the bulk of the activity occurred in earlier years. However, the decline from the peak in 2015 is notable. The limited threat to the United States is in large part the result of the enormous investment the country has made in strengthening its defenses against terrorism in the post-9/11 era. The United States spent $2.8 trillion on counterterrorism efforts from 2002 to 2017, constituting almost 15 percent of discretionary spending during that time frame.88 That effort has made the United States a hard target.89 On 9/11, there were 16 people on the U.S. “No Fly” list.90 In 2016, there were 81,000 people on the list.91 Before 9/11, there was no Department of Homeland Security, National Counterterrorism Center, or Transportation Security Administration. The United States benefits from a layered series of defenses that help to limit the ability of jihadists to mount complex operations within the country. Of the 19 cases so far in 2019, all but seven involved individuals monitored by an informant or undercover officer. Two of the 18 cases involved tips from family or community members who would have personally known the accused extremist, and in one case there was a tip from a suspicious member of the public. In January 2019, Director of National Intelligence Dan Coats testified that the United States is a “generally inhospitable operating environment” for homegrown violent extremists compared to most Western countries.92