The paper analyzes the evolution of public opinion attitudes on transatlantic issues in United States and the European countries. The paper distinguishes two main periods in Transatlantic Relations and examines the evolution of foreign policy attitudes in these two periods. A first period, during the Cold War, was characterized by a foreign policy consensus on both sides of the Atlantic. In Europe, this consensus was based on the combination of Atlanticism and Europeanism. With different emphasis in the different countries the Atlantic and European choice were seen as crucial to insure the domestic political stability and the foreign policy security. While in Europe the Cold War consensus was first based on an Center-Right coalition and later on extended to the Left, as a consequence of the post-Stalinism and the increasing institutionalization of European integration. In the United States it combined the Liberal and Conservative wings. This consensus broke down as a consequence of the Vietnam war and the détente crisis in the '70s. In Europe, the main consequence was the fracturing of the Left-Right consensus on foreign policy. This double cleavage has been brought forth during the Post-Cold War period and it has manifested itself in its starker way after the 9/11 events and a more unilateralist American foreign policy. The author discusses the different structure of public opinion in Europe ad the United States might have played in the tense relationships between Europe and US during the Iraq war.