A senior U.S. intelligence official says what he calls "the core al-Qaida" group has been degraded to the point where it can probably no longer carry out massive, complex attacks in the West.
The assessment was part of an annual security report given to Congress Tuesday by National Intelligence Director James Clapper.
He said that now, more than 10 years after the September 11th attacks, the United States faces a major threat from cyber-attacks and cyber-espionage. Clapper said "unsophisticated" attacks could penetrate poorly protected computer networks for power grids or similar systems.
Clapper also cited North Korea -- saying he does not believe the country's government would use nuclear weapons unless it perceived a threat to its survival. But he said it is not clear how Pyongyang would define such a threat, and that North Korea's nuclear and missile programs are a serious concern for the United States and East Asian nations.
On Iran, he said that country could not produce enough highly-enriched uranium for an atomic bomb without being detected.
Clapper was testifying before a Senate panel with new CIA Director John Brennan and FBI Director Robert Mueller.