奥巴马讲话 维护世界和平与安全 远离核恐怖主义
Hi, everybody. This week, I'm speaking to you from our Nuclear Security Summit. I welcomed more than 50 leaders from around the world to make sure we're working together to meet one of the greatest threats to global security — terrorists getting their hands on a weapon of mass destruction, like a nuclear weapon. Fortunately, because of our efforts so far, no te...