Many countries have excellent universities. There are, however, few world famous ones. These universities have achieved their fame through a combination of both their age and the high levels of quality in their instruction. Throughout their histories, each one has been a testing ground for the leadership of the nation. In the United States, Harvard and Yale attract thousands of foreign students who would use what they learn for the advancement of their own nations. In this way, these schools have developed an interesting method of international communication. Graduates around the world are able to connect with each other by having graduated from one of the finest universities in the world. Leaders in every field, whether government officials or ground-breaking scientists, who graduated from the same school have a direct link to each other and understand each other much better.