The Uruguayan Civil War (1839–1851), in which Brazil, France, Britain and the Argentine Confederation were involved, became an international conflict with humanitarian claims in favour of the besieged population of Montevideo with its prominent French community. General Juan Manuel de Rosas, governor of Buenos Aires with dictatorial powers, was allied against Montevideo, where many of his unitarian enemies had fled and where his regime was under attack through inflammatory newspapers and pamphlets. This chapter will examine the emotional strategies deployed by anti-Rosist dissidents in order to provoke a stronger involvement by France and Britain in support of Montevideo and the unitarians.