O'Connor had retired to his hacienda in Tarija after the tragic end of President Blanco, where he planned to remain unless called upon by his country. The possibility of a Peruvian invasion and the souring of relations between Peru and Bolivia compelled President
Andrés de Santa Cruz to recall O'Connor to active service. O'Connor accepted the President's call to arms, yet no war nor Peruvian invasion took place. Rather, after the defection of three Peruvian ships,
Agustín Gamarra chose to sign a treaty with Bolivia to ensure peace. Quiroga's invasion never came, and Santa Cruz attempted to incorporate an uninterested O'Connor into his administration. He served on an interim basis as Minister of War yet again in the year 1833, and was made President of the Council of War, for which he participated in the infamous trial of Colonel Manrique. Santa Cruz had wanted a death sentence for the colonel, however, when O'Connor ruled to fire Manrique from the army instead, a clash between the President and the Irishman took place. O'Connor, insulted by said clash, decided to retire to the borderlands in Tarija, declaring he would never serve in his administration again.
The war against Chile With the new Confederation secured, Santa Cruz made three major mistakes: the annulment of the treaty of peace and friendship with Chile; the promotion of the civilian
Mariano Enrique Calvo to
Division general; and marginalizing
José Miguel de Velasco, who had served loyally under Santa Cruz, which led to his later defection in
Tupiza in 1839. O'Connor describes these as "the major blunders which cost Santa Cruz", the first being the anger of the army at the promotion of Calvo:Congress passed a law... which had Doctor Mariano Enrique Calvo, Prosecutor of the Supreme Court and then appointed Vice President of Bolivia, in charge of the Executive Power in the absence of General Santa Cruz, promoted to division general. The soldiers of the army were very offended by the appointment of Calvo, and they told me that they did not want to accept a
peso of the money that had been granted to them by Congress, and that they did not approve and could not approve the appointment of a civilian to the rank of division general.The second major blunder which O'Connor describes is the annulment of the treaty with Chile signed under Salaverry, which had led to the declaration of war by said nation:[As for the war with Chile], the cause was the decree passed by General Santa Cruz which annulled the treaty of peace, friendship, and trade concluded between Salaverry, the intrusive president of Peru, and the Government of Chile... and the Captain General [Santa Cruz] knew it and must have weighed on him; however, he was so proud as a result of the victory at Socabaya that he imagined himself in a position to do whatever occurred to him at will, without looking at one side or the other, and this fact, which seemed insignificant to him, was the cause of his downfall and that of all the Confederation.The third major blunder O'Connor mentions is the disrespect toward and marginalization of General Velasco, whose defection in 1839 would be the event which finally toppled Santa Cruz in Bolivia:I received from Lima the plaque of a Great Dignitary of the Legion of Honor of Bolivia, which was worth the pension of five hundred
pesos for life. This dignity was not conferred on General Velasco, who had been Vice President of Bolivia for many years, and President also after the death of General Pedro Blanco, on the last night of 1828, and Chief of Staff of the Bolivian Army during the Battle of Yanacocha. Another reckless decision by General Santa Cruz, as this was the real cause behind the defection of General Velasco in Tupiza, and his pronouncement for the Restoration in February 1839, when he learned of the defeat of the Confederation Army in Yungay.The war with Chile continued when
Diego Portales was assassinated by his own men, followed by a mutiny in Oruro against Santa Cruz. Sensing an opportunity, the Chileans invaded Peru and were able to occupy the city of Arequipa. The Army of the Confederation far outnumbered that of the Chilean Army in Arequipa. However, instead of achieving a decisive and crushing victory over Chile, Santa Cruz opted for the signing of a peace treaty, known as the Treaty of Paucarpata, celebrated on 17 November 1837. O'Connor vehemently disagreed with such a treaty, telling Santa Cruz that he did not believe the Chilean government would abide by such a treaty. After the treaty was signed, Santa Cruz negotiated with General
Manuel Blanco Encalada the sale of all the horses in the Chilean Army in Arequipa, paying very high prices for the time.
The war against Argentina The
Argentine Confederation under
Juan Manuel de Rosas had, like the Chileans, also declared war on Santa Cruz. O’Connor was sent hurriedly to Tarija alongside General Braun to prevent the Argentine army under
Gregorio Paz from seizing the province. The Argentines intended to claim the province of Tarija, long disputed with Bolivia. Although the Bolivian high command believed the enemy was located in San Luis, the Argentines were actually advancing toward Tarija. O’Connor and Braun pursued Paz and eventually caught up to his army near the Montenegro mountain range, on the banks of the
Bermejo River on 24 June 1838. The Bolivians led an uphill charge against the Argentines, who were holding a defensive position. Although Paz's men were firing ferociously, the Bolivians under O’Connor led an impressive charge which resulted in the Argentine army abandoning their positions and fleeing to safety. Braun eventually caught up with O’Connor to discover the Argentine troops fleeing and abandoning all their belongings in the process. Thus, the
Battle of Montenegro came to an end with a decisive Bolivian victory. Previously, on 11 June, the second division of the Argentine army, led by
Alejandro Heredia, was defeated at the Battle of Iruya, completely repelling the attack of the enemies. When General Heredia was suddenly assassinated, the war on the south essentially ended, with the threat of an Argentine invasion eliminated. == Death and legacy ==