The integration between developed countries and developing ones is attracting the attention of the economic and finance people alike. The level of this integration has been more highlighted through the impact of the financial crisis on the United States economy and its reflection on regions and countries around the world. In this paper we employ econometric model and causality test to investigate if external shocks originated from the US economy play a pivotal role in influencing the macroeconomic fluctuations in different regions and countries around the world. The results show that the US economy is correlated with most of regions, but not with many individual countries; the US economic growth causes only the growth of 13 economies and 2 aggregate regions. This implies that the United States was not that successful in leading the campaign to persuade much of the world to follow its economic style.