For many years governments have conducted attacks in the name of somebody else, attacks blamed on somebody else, in order to deceive the public and instigate war. In American history we can count 9/11, the Gulf of Tonkin incident, Operation Northwoods, Pearl Harbor, the Lusitania, the Mexican American War, and the Spanish American War. Germany had the Reichstag fire. Italy had Operation Gladio. Way back in the day England had Guy Fewkes day.
The Operation Northwoods document, signed by the Chair of the Joint Chiefs of Staff (the entire U.S. military) is a fascinating historical record. When people say, “I just don’t believe the government could ever do this” they probably have not heard of false flag operations. 9/11 was qualitatively different in that for the first time it involved the government directly killing thousands of Americans, but in principle this had been done before.
Do a web search for “Operation Northwoods” and you can find the original document signed by Chairman of the Joint Chiefs Lyman Lemnitzer.
For example see this page: