A newly disclosed audio recording purportedly depicts a conversation between two American diplomats, in which one curses the European Union as they discuss how to handle turmoil in Ukraine. American officials were quick to suggest a Russian role in the apparent leak, which came as Russia is engaged in a tug of war with the E.U. and the United States for influence over Ukraine. The audio recording, incorporated into a video with Russian subtitles and posted on YouTube Tuesday, appears to be a conversation between the top U.S. diplomat for Europe, Victoria Nuland, and the U.S. ambassador to Ukraine, Geoffrey...