Zbigniew Brzezinski is a long time foreign policy expert and advisor to the U.S. government, former National Security Advisor to U.S. president Jimmy Carter, and is much listened to on the subject of maintaining the U.S. as the leading global power, specifically by way of being the dominant player in key geographies of Asia and Europe.
He gave a talk on foreign policy in April. The talk was held in Canada, and touched on the subject of U.S. geopolitical preeminence in the emerging multi-polar world.