In recent history, the biggest collaborative between nations has been the North American Free Trade Agreement. While its primary focus was the development of the Mexican, Canadian and U.S.’s economies, the precedence it set as a collaboration between governments was monumental.
The depression that struck the the Mexican government in the early part of the 1990’s affected the living standard of the average Mexican citizen, throwing the national government into a state of panic. Since the primary focus of a government is to serve as the voice of the people, the president of the Mexican government was forced to reach to his nearest, most affluent neighbor, the United States for a collaboration to stimulate his government. Eliminating things like trade taxes and customs fees encouraged American companies to operate freely between the U.S., Mexico and Canada.
Since NAFTA, the cooperation for the betterment of the nations has increased to the point where it is today.