Seen from Russia, 9/11 had a substantial impact on the Putin regime, then still in its infancy. The events of 9/11, which occurred less than 18 months after Vladimir Putin was elected president, confirmed the view of the new Russian elite that terrorism constituted the main threat to developed nations and should be fought using the harshest means. The War on Terror launched by the United States in response to 9/11 was thus used by Russia as a pretext for repressive policies toward anything and everything associated—rightly or wrongly—with Islamism, in particular the insurgencies in the North Caucasus. Simultaneously, 9/11 opened a unique window of cooperation between Washington, DC, and Moscow: Putin decided—over the objections of Russia’s Security Council and Armed Forces—to open a Russian military base to U.S. forces en route to Afghanistan and to allow Uzbekistan, and later Kyrgyzstan, to host U.S. bases. While both the bilateral relationship and the international context have changed dramatically over the past two decades, this last point invites us to remember that the US and Russia have been able to find areas of cooperation when both have needed them.