Global public opinion has emerged as a prominent issue in international relations. But have U.S. public diplomacy efforts during the post-9/11 period successfully improved foreign publics appraisals of U.S. foreign policy? We examine this question by estimating the effects of U.S. high-level visits to foreign countries on public opinion in those countries. We base our theoretical arguments on the political communication literature, but extend them to consider transnational dynamics in international relations. Specifically, we argue that U.S. leaders credibility in the eyes of foreign publics is critical in shaping attitudes toward U.S. foreign policy. Empirically, we show that the effects of such visits were initially significantly large and positive, but weakened once the war in Iraq began and international media started reporting negative aspects of the war on terror. Most interestingly, we find some evidence that high-level visits eventually exhibited a backlash effect.