The 85-year-old Grammy-winning crooner, famed for the 1960s hit single "I Left My Heart in San Francisco," made the remarks on the Sirius XM Radio talk show in New York on Monday.
Talking about the aftermath of the 2001 attacks on the World Trade Center, Bennett asked Stern "But who are the terrorists? Are we the terrorists or are they the terrorists? Two wrongs don't make a right."
Bennett said, "They flew the plane in, but we caused it. Because we were bombing them and they told us to stop."
But Bennett seemed apologetic in his latest Facebook posting, writing, "I am sorry if my statements suggested anything other than an expression of my love for my country, my hope for humanity and my desire for peace throughout the world."
He added, "I am so grateful to be an American and as a World War II veteran, I was proud to fight to protect our values, which have made America the greatest country on the planet. There is simply no excuse for terrorism and the murder of the nearly 3,000 innocent victims of the 9/11 attacks on our country."
"My life experiences --ranging from the Battle of the Bulge to marching with Martin Luther King -- made me a life-long humanist and pacifist, and reinforced my belief that violence begets violence and that war is the lowest form of human behavior," he continued.