Pentagon cancels plans to buy Russian helicopters --- (Reuters) - The Pentagon no longer will buy Russian helicopters for the Afghan Air Force from Rosoboronexport, a state-owned arms exporter that also sells weapons to the government of Syrian President Bashar al-Assad, U.S. defense officials and a leading Senate opponent of such deals said on Wednesday. -- The switch in Pentagon policy appears to end, at least for now, its plans to buy an additional 15 Russian Mi-17 helicopters for $345 million, sources familiar with the matter said. - More