In 1816 Lavalle moved to Mendoza to join the Army of the Andes of the "liberator" José de San Martín and fought in Chacabuco and the Maipú in Chile.But when he learned about the spiraling factionalist violence, San Martín realised that he would have to choose sides as the only actual way to govern, so he refused and returned instead to self-exile in Europe.Lavalle would be defeated a short time later at the Battle of Márquez Bridge by the forces of Juan Manuel de Rosas and Santa Fe governor Estanislao López.During the French blockade to the Río de la Plata, Fructuoso Rivera was reluctant to take military actions against Rosas, aware of his strength.Unitarians, who thought that the whole Argentine Confederation would rise against Rosas at the first chance, urged Lavalle to lead the attack, who requested not to share command with Rivera.At this juncture, however, France had given up its trust on the effectiveness of the blockade, as what was thought it would be an easy and short conflict was turning into a long war, without clear security of a final victory.Persecuted, his troops suffered constant attacks and Lavalle was forced to move further north, being defeated by Manuel Oribe in La Rioja and Tucumán.