For most of the last 70 years, the United States, Canada and much of Europe have constituted a vast zone of peace, prosperity and democracy. The trans-Atlantic community has grown to over 900 million inhabitants of more than 30 countries. It has set an example for regional cooperation in Africa, Latin America and Southeast Asia, and served as a mainstay of the liberal world order. That achievement is in jeopardy. The bonds within Europe have been fraying for some time, but this year has been the worst yet. Read Strobe Talbott's opinion on the decline of the West.