One option the U.S. and other nations have for ratcheting up pressure on Russia in response to its invasion of Ukraine is reducing their Russian energy purchases. U.K. Foreign Minister Liz Truss has proposed that the G7 nations – the U.S., U.K., Canada, France, Germany, Italy and Japan – impose limits on their Russian oil and gas imports. Global energy policy expert Amy Myers Jaffe explains how this strategy might work and how it could affect international oil markets, which have already been roiled by the conflict.