Guerriero (Warrior) from the mid-1950s reflects the psychological impact of mechanized warfare. The bulbous, Etruscan style of Marini's earlier sculptures is replaced by an industrialized angularity, giving the horseman and his rider the appearance of a battlefield howitzer. The scarred bronze surfaces and aggressive, jutting limbs of this work distort the smooth pastoral vision of his earlier work, recalling Picasso's Guernica as a symbol of humanity barbarized by conflict. The symbolic significance of the Warrior series was quickly grasped by Marini's public, and in 1960 the Germanisches Nationalmuseum in Nuremberg purchased a large version of the subject as a memorial of the horrors of war. However the forms of this work also look forward to a nightmarish vision of the future; as Marini told a critic in the late 1950s, “If the whole earth is destroyed in our atomic age, I feel that the human forms which may survive as mere fossils will have become sculptures similar to mine” (quoted in ibid., p. 21).

The mechanization of the figure of the horse and rider is a bitter parody of the ideals of an earlier generation of Italian artists such as Marinetti; he and his Futurist colleagues believed war was a means of cleansing the human race and dreamt of “metallization of the human body.” In Marini's work the jagged lines and savage symmetries no longer evoke a mechanized perfection, but instead signify the brutalization of both man and beast as a result of industrialized slaughter on the battlefields of Europe. The abstraction of form is not an aesthetic purification of the horse and rider but a warped vision of nightmarish realism; as Marini commented, “the residue of a series of devastations, emerging from such conflicts, could naturally bring about this new realism, but it would be indelibly smeared with the dirt of bit.mes n. It could become a diabolical realism, like that of a Dante, returned to poke his fingers into people's eyes” (quoted in ibid., pp. 26-27).