Fútbol, soccer, the Beautiful Game. Often, political rivalries are played out on the field, like between the United Kingdom and Argentina at the 1986 World Cup in Mexico; it was Argentina's chance to avenge its defeat at the hands of the Brits in the Falklands War. When Iran and the United States played each other for the first time since the Hostage Crisis at the 1998 World Cup in France, that game went off without a hitch. But the same did not hold true when El Salvador played Honduras in a three game qualifying series. 

Honduras won the first game (in Honduras). Then El Salvador won the second game (in El Salvador). When El Salvador won the third game in Mexico, all hell broke loose. Literally.

El Salvador was and is one of the most densely populated countries in the Americas. Honduras, in comparison, was and is sparsely populated. By the end of the 1960s, over 300,000 Salvadorians were living and working (often illegally) in Honduras. The dilemma posed by these immigrants, many of whom cultivated previously unproductive land, was addressed through a series of bilateral agreements between the two Central American nations. The last of these agreements, conveniently, expired in 1969. 

To make matters worse, the government in Tegucigalpa, the capital of Honduras, initiated land reform that effectively kicked Salvadorians off the land. Thousands fled back to El Salvador. Then, El Salvador started claiming the land that had previously been held by its citizens in Honduras as El Salvador's. It was in this climate that the two countries met on the soccer field to determine who would qualify for the 1970 World Cup in Mexico. 

The first game was played in Tegucigalpa. Hondurans made sure their rival team did not have a good night's rest by creating as much noise as possible outside their hotel rooms. El Salvador lost. Then the media in San Salvador started reporting that a young woman, so distraught after the loss, had shot herself in the heart. El Nacional wrote, "The young girl could not bear to see her fatherland brought to its knees." She was given a televised funeral and the President himself walked behind her casket. By the time the Honduran team got to San Salvador to play the second game, tensions were at an all-time high. At the game, which El Salvador won, the Honduran flag was not flown during the opening ceremony. In it place, Salvadorian officials placed a rag. 

The El Salvador team ahead of the World Cup play-off against Honduras in Mexico via home.bt.com

With the threat of all violence at the last game (it was to the best of three) a very real possibility, FIFA officials decided to hold the third game in Mexico City. 5,000 Mexican police officers kept both sides fairly under control. El Salvador went on to win the Mexico City game. Hours later, El Salvador severed all diplomatic ties with its northern neighbor. A mere two weeks later, the Salvadorian air force dropped bombs on Tegucigalpa.  

La guerra del fútbol was obviously not fought over simply over soccer. But the games were used as incredible and very effective propaganda tools. The war lasted one hundred hours. Blocked by a US arms embargo from directly purchasing weapons, both sides had to buy outdated military equipment from World War II. This war was the last time the world saw fighters armed with pistols dueling one another.

After the Organization of American States brokered a cease-fire, between 1,000 to 2,000 people were dead. 100,000 more were displaced. A formal peace treaty was not signed until 1980. Although the war only lasted four days, the consequences for El Salvador were immense. Thousands of Salvadorians could no longer return to Honduras, straining an already fragile economy. Discontent spread, and just ten years later the country plunged into a twelve-year civil war that left 75,000 dead