WASHINGTON (Reuters) - Despite levying six rounds of increasingly tough economic sanctions against Russia for its actions in Ukraine, President Barack Obama has left two rich targets untouched: Moscow's natural gas export behemoth and its main weapons exporter.
Financial warfare against Gazprom or Rosoboronexport could invite Russian retaliation against U.S. European allies and negative consequences for Washington - highlighting the dilemmas Obama faces as he weighs how to respond to the shoot-down of a Malaysian airliner over eastern Ukraine on Thursday.