Drone aircraft spy on and attack terrorists with no pilot in harm's way. Small teams of special operations troops quietly train and advise foreign forces. Viruses sent from computers to foreign networks strike silently, with no American fingerprint. It's war in the shadows, with the U.S. public largely in the dark. The high-tech warfare allows Obama to target what the administration sees as the greatest threats to U.S. security, without the cost and liabilities of sending a swarm of ground troops to capture territory; some of them almost certainly would come home maimed or dead. But it also raises questions about accountability and the implications for international norms regarding the use of force outside of traditional armed conflict. Congressional oversight of these operations appears to be cursory and insufficient," said Steven Aftergood, an expert on government secrecy issues for the Federation of American Scientists, a private group. "It is Congress' responsibility to declare war under the Constitution, but instead it appears to have adopted a largely passive role while the executive takes the initiative in war fighting," Aftergood said in an interview. That's partly because lawmakers relinquished their authority by passing a law just after the Sept. 11 [attacks]. In this shroud of secrecy, leaks to the news media of classified details about certain covert operations have led to charges that the White House orchestrated the revelations to bolster Obama's national security credentials and thereby improve his re-election chances.