The Platine War (Spanish: Guerra Platina, Portuguese: Guerra do Prata, Guerra contra Oribe e Rosas; 18 August 1851 – 3 February 1852) was fought between the Argentine Confederation and an alliance consisting of the Empire of Brazil, Uruguay, and the Argentine provinces of Entre Ríos and Corrientes, with the participation of the Republic of Paraguay as Brazil's co-belligerent and ally. The war was part of a decades-long dispute between Argentina and Brazil for influence over Uruguay and Paraguay, and hegemony over the Platine region (areas bordering the Río de la Plata). The conflict took place in Uruguay and northeastern Argentina, and on the Río de la Plata. Uruguay's internal troubles, including the longrunning Uruguayan Civil War (La Guerra Grande – "The Great War"), were heavily influential factors leading to the Platine War.
In 1850, the Platine region was politically unstable. Although the Governor of Buenos Aires, Juan Manuel de Rosas, had gained dictatorial control over other Argentine provinces, his rule was plagued by a series of regional rebellions. Meanwhile, Uruguay struggled with its own civil war, which started after gaining independence from the Brazilian Empire in 1828 in the Cisplatine War. Rosas backed the Uruguayan Blanco party in this conflict, and further desired to extend Argentine borders to areas formerly occupied by the Spanish Viceroyalty of the Río de la Plata. This meant asserting control over Uruguay, Paraguay, and Bolivia, which threatened Brazilian interests and sovereignty since the old Spanish Viceroyalty had also included territories which had long been incorporated into the Brazilian province of Rio Grande do Sul.
Brazil actively pursued ways to eliminate the threat from Rosas. In 1851, it allied with the Argentine breakaway provinces of Corrientes and Entre Ríos (led by Justo José de Urquiza), and the anti-Rosas Colorado party in Uruguay. Brazil next secured the south-western flank by signing defensive alliances with Paraguay and Bolivia. Faced with an offensive alliance against his regime, Rosas declared war on Brazil.
Allied forces first advanced into Uruguayan territory, defeating Rosas' Blanco party supporters led by Manuel Oribe. Afterwards, the Allied army was divided, with the main arm advancing by land to engage Rosas' main defenses and the other launching a seaborne assault directed at Buenos Aires.
The Platine War ended in February of 1852 with the Allied victory at the Battle of Caseros, for some time establishing Brazilian hegemony over much of South America. The war ushered in a period of economic and political stability in the Empire of Brazil. With Rosas gone, Argentina began a political process which would result in a more unified state. However, the end of the Platine war did not completely resolve issues within the Platine region. Turmoil continued in subsequent years, with internal disputes among political factions in Uruguay, a long civil war in Argentina, and an emergent Paraguay asserting its claims. Two more major international wars followed during the next two decades, sparked by territorial ambitions and conflicts over influence.
Background
Rosas rule in Argentina
Don Juan Manuel de Rosas became governor of Buenos Aires after the brief period of anarchy following the end of the Cisplatine War in 1828. In theory, Rosas only held as much power as governors of the other Argentine provinces, but in reality, he ruled over the entire Argentine Confederation, as the country was then known. Although he was one of the Federalists, a faction which demanded greater provincial autonomy, in practice Rosas exercised control over the other provinces, having become a virtual dictator of Argentina. During his 20-year government, the country witnessed the resurgence of armed conflicts between the Unitarians (his rival political faction) and the Federalists.
Rosas desired to recreate the former Viceroyalty of the Río de la Plata, created by the Spanish king Charles III in 1776 and which was extinguished in 1825. He aimed to build a powerful, republican state with Argentina placed at the center. The defunct Viceroyalty had shattered into several separate nations following the Argentine War of Independence at the beginning of the 19th century. To achieve reunification, the Argentine government needed to annex the three neighboring countries – Bolivia, Uruguay and Paraguay, as well as to incorporate a portion of the southern region of Brazil. Rosas first had to gather allies across the region who shared his vision. In some instances, this meant that he had to become involved in the internal politics of neighboring countries, backing those sympathetic to union with Argentina, and occasionally even financing rebellions and wars.
Paraguay
Paraguay considered itself a sovereign nation since 1811, but it was not recognized as such by any other nation. Argentina viewed it as a rebellious province. The Paraguayan dictator José Gaspar Rodríguez de Francia decided that the best way to maintain his own rule and the independence of Paraguay from Argentina was to isolate the country from contacts with the outside world. It was for this reason that, up until 1840, Paraguay had avoided establishing diplomatic relations with other nations. With the death of Francia, this policy began to shift, and his successor Don Carlos Antonio López signed two treaties in July 1841. These were the "Friendship, Commerce and Navigation" and "Limits" agreements made with the Argentine province of Corrientes, which itself had broken away from Argentina under Rosas. Meanwhile, Rosas increasingly put pressure on Paraguay. He continued to refuse to recognize Paraguayan independence and placed a blockade on international traffic to and from Paraguay on the Paraná River.
Paraguay held its own conflict against Juan Manuel de Rosas receiving very substantial support from the Empire of Brazil. President Carlos Antonio López declared war against Rosas and in the first phase of the "Paraguayan front" (1845–1846), Paraguay invaded the Province of Corrientes hoping to cause a rebellion alongside the Argentine dissidents led by Gen. José María Paz, which fared poorly. In the second phase however (1847–1850), the Paraguayans under Gen. Francisco Solano López occupied the Province of Misiones which was under Rosas' rule, resisting in their positions while suffering heavy losses against the counterattacks of the forces of Buenos Aires.
The friendship and alliance between the Republic of Paraguay and the Empire of Brazil remained strong until 1852, when Rosas was finally overthrown. In fact, the Brazilian diplomacy played a key role for the recognition of the Independence of Paraguay. On the other hand, Paraguay gave its full support to Brazil, fighting its own campaign against Buenos Aires. However, in the final phase of the conflict (1851–1852), President Carlos López refused to join forces with the Allied army, keeping a defensive role (as established with Brazil). This was because López was very suspicious of Justo José de Urquiza, former General of Rosas' army who became the leader of the Argentine insurrection.
Uruguayan conflict
The old Brazilian province of Cisplatina had become the independent Oriental Republic of Uruguay after the Cisplatine War of the 1820s. The country soon was engulfed in a long civil war between its two political parties: the Blancos, led by Don Juan Antonio Lavalleja, and the Colorados, led by Don Fructuoso Rivera.
Lavalleja soon discovered that Rosas in neighbouring Buenos Aires was interested in aiding him financially and militarily. In 1832, Lavalleja began to receive aid from Bento Gonçalves, a soldier and farmer from the Brazilian province of Rio Grande do Sul. Gonçalves had been encouraged by Rosas to rebel against the Brazilian government in 1835, with the ultimate aim of enabling Argentina to annex the province of Rio Grande do Sul. Together, Lavalleja and Gonçalves initiated a military campaign in Uruguay which was characterized by extensive violence and pillage. Gonçalves betrayed Rosas and Lavalleja by becoming an ally of Rivera. Both then invaded Uruguay and overran most of the country outside the environs of the capital, Montevideo. Defeated, the then-Uruguayan president Manuel Oribe, like the betrayed Lavalleja a member of the Blanco party, resigned his position as president and fled to Argentina.
Rosas was determined to restore Argentine suzerainty over Uruguay and take revenge on Gonçalves. A series of interventions resulted. In 1839 an army led by Lavalleja, Oribe and Justo José de Urquiza, (Governor of Entre Rios) was quickly defeated by Rivera. At this point, Lavalleja turned his back on the conflict and played no further part in the civil war. Rosas sent another army of Argentines and Uruguayans in 1845, led by Oribe and Urquiza, and this time defeated Rivera's forces, slaughtering the survivors. Rivera was one of the few who managed to escape, and went into exile in Rio de Janeiro. What remained of Rivera's Colorados held power only in the country's capital, Montevideo, as Oribe's forces began the Great Siege of Montevideo. The violence in Uruguay escalated, with Oribe's men killing more than 17,000 Uruguayans and 15,000 Argentinians during the conflict.
Oribe's control of nearly all of Uruguay had been secured, enabling him to launch an invasion of southern Brazil, his forces stealing cattle, looting ranches, and liquidating political enemies as they went. More than 188 Brazilian farms were attacked, with 814,000 cattle and 16,950 horses stolen. Local Brazilians independently decided to retaliate, making raids into Uruguay which became known as "Califórnias", in reference to the violence in western North America during California's revolt against Mexico, its brief independence and subsequent annexation by the U.S. As conflict further escalated with the persistent support of Rosas for the Blancos, anarchy spread over wide areas in the region; with a growing threat to trade, the era's two greatest powers, France and the United Kingdom, were induced to declare war on Argentina and impose a blockade on the Río de la Plata. Buenos Aires was repeatedly bombarded by the Anglo-French fleet. The Argentine government was able to mount an effective resistance, however, leading to a peace accord in 1849.
Empire of Brazil reacts
By the middle of the 19th century, the Empire of Brazil was the richest and most powerful nation in Latin America. It thrived under democratic institutions and a constitutional monarchy and prided itself on the absence of caudillos, dictators and coups d'état which were common across the rest of the continent. During the minority of emperor Pedro II, which led to the regency period in the 1830s, however, there had been several internal rebellions driven by local disputes for power within a few provinces. One of these, the Ragamuffin War, had been led by Gonçalves, as noted above.
For the Brazilian Empire, expansionist plans on the part of powerful, republican Argentina represented an existential threat. It also meant a threat to Brazilian hegemony across its southern borders. A successful Argentine bid to incorporate Paraguay and Uruguay into a reconstituted Viceroyalty of the Río de la Plata (and control of the Platine river network consequently passing into entirely hostile hands) would have threatened to cut communication between the Brazilian province of Mato Grosso and Rio de Janeiro. With river transportation denied, the alternative land routes would require months of travel instead of days. Nor was Brazil keen to share a direct border with Argentina, fearing an increased vulnerability to an invasion by Rosas.
The members of the Brazilian Cabinet could not reach agreement as to how to address the danger posed by Rosas. Some ministers advocated seeking a peaceful resolution at any cost. These feared Brazil was unprepared for war and that a defeat would lead to a situation similar to the chaos following the loss of Cisplatina in the 1820s, which ended in abdication by Dom Pedro I, the Emperor's father. Other ministers took the position that only a military response would eliminate the threat. In 1849, however, Paulino José Soares de Sousa, a member of the pro-war faction and later Viscount of Uruguai, was chosen as the new minister of Foreign Affairs. Soares made clear his intent to deal with Argentina without foreign assistance, announcing that the "Imperial Government does not desire or judge convenient an alliance with France or any other European nation related to the matters in the Platine region. It understands that they must be resolved by the nations which [we] are closely connected with... It will not admit European influence over America." The Empire of Brazil was determined to extend its zone of influence over South America.
The cabinet settled upon a risky alternative to resolve the complicated situation in the Platine region. Instead of undertaking a period of conscription to build up the Imperial Brazilian Army, which would have been costly, the Council decided to rely on the standing army. It sent a contingent south to secure the region. Brazil held an advantage in possessing a powerful and modern navy, along with an experienced professional army hardened by years of internal and external warfare. Up until this point, no other nation in South America possessed true navies or regular armies. Rosas' and Oribe's forces were largely made up of irregular troops on loan from those caudillos who supported them. Even a decade later, Argentina could only field an army of 6,000 men. Brazil also decided to adopt Rosas' own tactics by financing his opponents to weaken him both internally and externally.
Alliance against Rosas
The Brazilian government set about creating a regional alliance against Rosas, sending a delegation to the region led by Honório Hermeto Carneiro Leão (later the Marquis of Paraná), who held plenipotentiary authority. He was assisted by José Maria da Silva Paranhos (later the Viscount of Rio Branco). Brazil signed a treaty with Bolivia in which Bolivia agreed to strengthen its border defenses to deter any attack by Rosas, though it declined to contribute troops to a war with Argentina.
Isolationist Paraguay was more difficult to win over. Brazil made the initial overtures, becoming the first country to formally recognise Paraguayan independence in 1844. This soon led to the establishment of excellent diplomatic relations. The Brazilian ambassador in Paraguay, Pimenta Bueno, became a private councilor to President Carlos Antonio López. A defensive alliance was signed on 25 December 1850 between Brazil and Paraguay, in which López agreed to supply the Empire with horses for its army. But Paraguay refused to contribute troops to fight Rosas, believing that Justo José de Urquiza (who had invaded Uruguay in 1839 and in 1845), the ruler of the Argentine Entre Ríos province, secretly wished to annex Paraguay.