Suicide bombers have not hit the United States since the 9/11 terrorist hijacking attacks, but they remain a constant concern because of their prevalence around the globe and determination to die for their causes, according to the FBI's chief of counterterrorism. He does not believe America is overflowing with homegrown terrorists, but Joseph Billy said "a significant number" of attacks have been thwarted since airliners were crashed into the World Trade Center, the Pentagon and a Pennsylvania farm field on Sept. 11, 2001. While declining to divulge the nature of the averted plots, Billy credited intelligence that led to either fortified security around potential targets or identification of suspected terrorists. Authorities recently stopped homegrown plots targeting the Fort Dix military base in New Jersey and a jet fuel pipeline at New York's Kennedy International Airport. Billy, the FBI assistant director in charge of counterterrorism, made his comments during a rare wide-ranging interview with The Associated Press, days before the failed car bombing in London and the airport bombing in Glasgow.