US National Security Adviser Says Pakistan Is Top U.S. Challenge

The biggest foreign-policy challenge awaiting President-elect Barack Obama isn't Iraq or Afghanistan but Pakistan, President George W. Bush's national-security adviser said.

In an interview previewing a valedictory speech he plans to give on Wednesday, National Security Adviser Stephen Hadley said Pakistan's increasingly turbulent border region poses threats not just to the U.S. mission in Afghanistan, but also to neighboring India, as evidenced by the recent Mumbai terrorist attacks, as well as to urban areas of Pakistan itself -- and the world beyond.

If extremists succeed in destabilizing Pakistan, the resulting chaos will threaten the entire region, Mr. Hadley is expected to say in his speech.