In 1937, after the disastrous Chaco War, which was ostensibly fought over oil reserves near the border with Paraguay, Bolivia expropriated the holdings of the Standard Oil Company and formed its own state oil firm, ypfb. However, national control over natural resources declined after 1955, when the Revolutionary Nationalist Movement (mnr) government, as a concession to the United States, passed a new petroleum code favoring U.S. companies. The Bolivian Gulf Oil Company soon became the largest hydrocarbon producer in the country. In the 1960s, under the right-wing dictatorship of René Barrientos Ortuño, new concessions were granted to private corporations, and by 1968, Bolivian Gulf Oil was producing forty thousand barrels per day and held reserves that were ten times larger than those of ypfb. For critics on the left, such as Marcelo Quiroga Santa Cruz, Bolivian Gulf Oil constituted a new “superstate” comparable to the powerful tin-mining bloc prior to the revolution of 1952. After Barrientos’s death, the moderate reformist General Alfredo Ovando Candia seized power in 1969. Influenced by the nationalist military regime in Peru at the same time, Ovando sought to court the left and the trade-union movement and to stake a bold claim to popular legitimacy. With Marcelo Quiroga Santa Cruz as his minister of mines and petroleum, he dramatically declared the nationalization of Bolivian Gulf Oil on 17 October 1969. With the recuperation of Bolivia’s precious oil, Ovando proclaimed, “The blood spilled in the Chaco was not in vain.”