 Following his imprisonment he sought political asylum in Montevideo in 1962 and soon made contact with revolutionary elements in that country.The first edition of "Strategy of the Urban Guerrilla" was published in 1966.It served as a counter to the rural insurrectionist methods espoused by Che Guevara, although Guillen did agree with Guevara on several key issues and even authored the introduction to the Uruguayan edition of Guevara's "Guerrilla Warfare".