US drone war under scrutiny after botched strike

President Barack Obama's admission that a US drone strike accidentally took the lives of two hostages has raised fresh questions about the limits and the risks of the country's "targeted killing" campaign. Since taking office in 2009, Obama has relied heavily on drone raids to hunt down Al-Qaeda leaders and other Islamist extremists from Pakistan's tribal areas to Somalia and Yemen. The White House also admitted that US intelligence was flawed for another drone strike at