Russia is promising retaliation against nations backing Ukraine, and some predict that it will take the form of disrupting gas supplies to Europe. Rice University energy expert Gabe Collins says that would have global effects. Russia exports around five-million barrels of crude oil per day. He says there is no way to replace that quickly if the taps get shut off. Discussions have already begun where the U.S. is persuading liquefied natural gas suppliers to redirect cargoes to Europe.