U.S. officials on Saturday will test the government’s ability to respond to attacks inside the United States that use improvised explosive devices, or IEDs, the White House said. In the “tabletop” exercise, officials from security agencies, including the FBI, Defense Department and Department of Homeland Security, will meet in the office building adjacent to the White House and discuss how they would react to a fictional scenario of several IED attacks around the country. White House spokesman Scott Stanzel said the exercise was not in response to any current threat. Full Story