Brazil borders all South American countries except Chile and Ecuador. Most of these borders are porous and have common problems, such as smuggling and drug and arms trafficking. Brazil's border with Uruguay, however, differs from all the others, as it is probably the friendliest border in the region.
Relations between Brazil and Uruguay were not always good. Brazil annexed what is now Uruguay in 1820, and that caused animosity not only between Brazil and Uruguay, but also with Argentina, which feared Brazil's expansionist policies. Following a three-year war between exiled Uruguayan officers (supported by Argentina) and Brazil, Uruguay attained independence in 1828. This new nation became a buffer state between Argentina and Brazil.
Throughout the rest of the 19th century, relations with Brazil improved. In 1843, Montevideo requested military help from Brazil when Argentine troops, in concert with supporters of Uruguay’s second president, Manuel Oribe, attempted to invade the capital. Argentina continued to threaten Uruguay's territorial integrity until 1851, when the Great War — fought between Argentina-backed adherents to Oribe and Brazil-backed supporters of Uruguay's first president, Jose Fructuoso Rivera — came to an inconclusive end. The War of the Triple Alliance, in which Brazil, Uruguay and Argentina worked together to subdue a threatened Paraguay, further solidified cordial relations between Brazil and Uruguay.
The reality along the Brazilian-Uruguayan border in the 21st century, however, differs greatly from that of the 19th century, when both countries were trying to define their borders after gaining independence from Spanish rule. People in cities and small communities along this border have many cultural similarities. They tend to speak a sort of portunol — a mix between Spanish and Portuguese. Music, food and religion are similarly shared. People on both sides of the border listen to milonga and chamame music, just as yerba mate tea and barbecued meat are an important part of their diets. Residents of these communities tend to work and attend schools, go to hospitals and seek other social services on both sides of the border, depending on which city has the best facilities.
The cities of Santana do Livramento and Rivera offer a good example of how well integrated communities on both sides of the border are. Livramento is the city on the Brazilian side of the border, while Rivera lies on the Uruguayan side, but the two function more or less as one city. A monument in International Park marks the international border. The obelisk legally separates both countries. No border guards; no passport control. Anyone can cross without showing identification.
Other cities along the border, such as Acegua-Brazil and Acegua-Uruguay, have the same arrangement. Once, I was in Acegua on my way to Montevideo and I needed to get paperwork for my vehicle. I had to ask where the customs office was because it was not located on the border that separates both countries.
There is one rivalry in these cross-border towns, however, that hasn't been resolved. On the contrary, it has been exacerbated in recent years. Whenever there is a soccer game between Uruguay and Brazil, the compatriots of the winning team cover the border monuments with their national flag. This year's World Cup should make for some colorful cross-border displays.