The first 100 years of Spanish-U.S. relations was marked by violence and hostility. Spanish-U.S. relations began in the late eighteenth century, with conflict over Spanish possessions in America. The treaty of San Lorenzo was signed in the last years of the eighteenth century to establish friendly relations between the two countries, secure free navigation for the U.S. in the Mississippi River, and establish the Florida border. But conflicts over the Florida border persisted until the Transcontinental Treaty of 1821, when Spain surrendered the territory to the U.S. In 1898 the Spanish-American War between the two countries further soured Spanish-U.S. relations. As a result of the war, Spain ceded Puerto Rico, the Philippine Islands, and Guam to the United States and abandoned all claims to Cuba, which became independent in 1902.

For the rest of the twentieth century, Spanish-U.S. relations remained tepid, with no country showing preferential treatment towards the other. However, in the twenty first century, Spain and the U.S. are strong allies in the fight against terrorism. Spain’s support to the U.S. is vital because of Spain’s geographic location on the Mediterranean. The U.S. military has two large bases in southern Spain. The U.S. Naval base is located in Rota, which is in southwestern Spain, halfway between Gibraltar and the Portugal border. The U.S. Air base is located in Moron, which is southeast of Seville and about seventy five miles northeast of the base in Rota. The bases enable mobilization for and transportation of American forces. But, the cordial relations suffered a jolt when Spanish Prime Minister Zapatero announced the withdrawal of 1,300 Spanish troops from Iraq.

The closeness of Spanish-U.S. relations is exemplified by a number of treaties and agreements that have been re-ratified or have newly come into force. The agreements cover a wide variety of areas, from education and employment to scientific cooperation, space, and defense. Diplomatic visits have also been central to the bilateral relationship and have intensified since September 11, 2001. In trading terms, the two countries have a healthy relationship: during the first nine months of 2003 U.S. exports to Spain amounted to US$4,189 million, and the United States received nearly US$4,884 million in Spanish imports.

The two countries also cooperate in several other important areas. The U.S. National Aeronautics and Space Administration (NASA) and the Spanish National Institute for Aerospace Technology (INTA) jointly operate the Madrid Deep Space Communications Complex in support of Earth orbital and solar system exploration missions. After Obama’s ascent to power as the President of the U.S., the Spanish Foreign Minister Moratinos is known to have stated that “a new stage in relations between the United States and Spain is opening that is more intense, more productive.”