The ranking of the United States in major international tests such as the Progress in International Reading Literacy Study (PIRLS), Trends in International Mathematics and Science Study (TIMSS), and Program for International Student Assessment (PISA) is used as the driving force and rationale for the current educational reforms in the United States. Through current reforms, the United States is preparing to "race to the top" of the international rankings. However, using international test results as the ultimate indicator of a country's educational achievement might not be an appropriate measure. Additionally, replicating some aspects of high-achieving countries' education systems or standards may not guarantee success for U.S. public schools. In this article, four reasons are presented explaining why there is no guaranteed success in comparing the United States to other countries' educational standards and to their achievement in international tests. In order to successfully implement reforms in U.S. public schools, educational leaders and reformers should carefully consider the four points discussed in this article and use tests to inform their reforms, rather than to create uniformity.