A profile of the international terrorist network that the United States has singled out as the most serious threat to U.S. security.

Western Europe’s burgeoning Islamic population continues to spark concerns about Muslim assimilation and a cultural divide.

A possible transfer of political power in the congressional midterm elections could doom short-term chances for a comprehensive climate bill. But experts say climate issues could still be addressed t…

Pakistan is key to success in U.S.-led  counterterrorism efforts, with its tribal areas serving as terrorist havens. But covert U.S. military actions inside Pakistan put the future of the U.S.-Pakist…