Secretary General Jens Stoltenberg joined US Permanent Representative Kay Bailey Hutchison at the 9/11 and Article 5 Memorial at NATO Headquarters on Wednesday (11 September 2019), for a ceremony commemorating the 18th anniversary of the 2001 terrorist attacks on the United States. Mr. Stoltenberg recalled that the attack led to the invocation of the Alliance's collective defence clause for the first and only time in history, and that Allies stand united in the "global, generational fight" against terrorism. He said: "Europe and North America must continue to stand together now as we stood together on 9/11, united in our commitment to protect our people and our values."