The war in Iraq has become a primary recruitment vehicle for violent Islamic extremists, motivating a new generation of potential terrorists around the world whose numbers may be increasing faster than the United States and its allies can reduce the threat, U.S. intelligence analysts have concluded.

A 30-page National Intelligence Estimate completed in April cites the "centrality" of the U.S. invasion of Iraq, and the insurgency that has followed, as the leading inspiration for new Islamic extremist networks and cells that are united by little more than an anti-Western agenda. It concludes that, rather than contributing to eventual victory in the global counterterrorism struggle, the situation in Iraq has worsened the U.S. position, according to officials familiar with the classified document.