In the wake of the September 11, 2001, terrorist attack in Manhattan, Papadakos performed in "An Evening of Peace" gathering at nearby Riverside Church, joining other activists including Vietnamese Buddhist monk Thích Nhất Hạnh, Judy Collins, and Paul Winter. The concert's theme was criticized afterwards by Kay S. Hymowitz and Harry Stein, writing in "The Wall Street Journal". The columnists decried what they called "multiculturalism, the enemy within," saying it was at variance with the majority of American opinion favoring a sustained military response.