A few years, an Uruguayan soldier surprised me--almost shocked me, really--when he said "We should be part of Argentina." On a superficial level, it might make sense, and the two countries are already part of Mercosur, the South American common market that also includes Brazil and Paraguay. Their accents are similar enough that, for a non-native speaker, it's hard to tell them apart. Uruguayans eat as much or more beef than Argentines, and drink as much or more mate.
At the same time, the two countries have often had a contentious relationship. In the mid-19th century, Argentine dictator Juan Manuel Rosas blockaded the port of Montevideo for years. At present, Argentine protestors from Gualeguaychú have blocked the border crossing there because of an ostensibly polluting pulp plant on the Uruguayan side.
All this came to mind today as I visited the Uruguayan resort of Punta del Este, the playground for rich and famous Argentines whose primary occupation appears to be posing for papparazzi. In January and February, many of them anchor their boats in Punta del Este's yacht harbor and party until dawn. One of them, Porteño publicist Gabriel Alvarez, is in prison awaiting trial here after his driver killed two Argentine motorcyclists in a high-speed collision on Punta's outskirts (the Buenos Aires daily La Nación keeps a bureau in Punta del Este to report on the doings of Argentines here).
In area, Argentina (the world's eighth-largest country) is about the size of India, while Uruguay is a little bigger than England. Argentina's population (around 39 million) is more than ten times that of Uruguay's 3.4 million or so. For their economic well-being, Uruguayans need Argentines, even if they feel ambivalent about them. In a sense, Uruguayans share the dilemma of Canadians, who also share a long border with a sometimes overbearing neighbor who's also a relative and trading partner.
Argentina and Uruguay will always have differences, but it could be far worse. After I remarked to a Montevideo friend that Argentina was the size of India, we speculated that a similarly densely populated Argentina would mean a billion Argentines--including 300 million Porteños--facing Uruguay's shores.