The vast majority of Argentina’s soy products are exported, mostly to China. Rising Asian demand — for soy sauce, tofu, animal feed — has fueled the explosion of the soybean industry across Argentina, Brazil and Paraguay. The pattern is a familiar one for Argentina. A century ago, it became one of the world’s wealthiest countries on a per-capita basis by shipping the pampa’s abundant yields of grain and beef to Europe. Today, however, it is the price of soybean futures that dominates the electronic tickers on the wall. Last year, Argentina exported $17 billion in soybean products, more than a quarter of its overall export earnings. Over the past decade, China has more than doubled its overall trade with Latin America and the Caribbean, to $244 billion in 2017, elevating China past the United States as the region’s top trading partner, a stunning development in America’s own backyard.