Massive terrorist attack could occur within two years.

• Author: Book, Elizabeth G.
• Position: Security Beat

The United States could see a large-scale terrorist attack on its soil in about two years, according to the author of the book "Jihad in America." It takes Al-Qaeda operatives two to two and a half years to regroup and plan attacks, said Steven Emerson, who is executive director of the Investigative Project on Public Television.

Each one of the attacks, he said, "is trying to surpass the previous one in scope and its damage," he said.

"We could assume, although I don't have any empirical evidence to suggest this, that there are cells that are being instituted right now, or that are in place that are tasked with...a future attack on American soil that will be more devastating than the 9/11 attacks."

Emerson made his comments at the National Security Strategy and Policy conference organized by the Institute for Foreign Policy Analysis.

"I have no broad intelligence...