The ardor in combat, the abnegation of the volunteers of the brigades is recognized even in the opposing camp. In his Military History of the Spanish War, published in Madrid in 1961, the Francoist writer Manuel Aznar writes for example:"Seeing these men who had come from all over the world, a sort of revolutionary foreign legion which fought with so much faith and in contempt of death, the militiamen regained courage and confidence in victory. "
A British Conservative MP, Mac Namara, who came to Republican Spain on a parliamentary mission, noted for his part:"In my life, I have never seen a troop similar to the international brigades. Their bravery is admirable. Most receive the baptism of fire. Smoking a cigarette so they can ignite the flare of their primitive hand grenades, learning strategy on the battlefield, they are not unwavering wills. The Italians are particularly fierce. "
Let us quote again this testimony of the French journalist Louis Delaprée, special correspondent of Paris-Soir, who will find himself death in Spain:"This heroic troop does not affect a Maravedis, but his morale is no less good than his physical condition. All are aware of fighting against a thousand-headed hydra which they call fascism with the same horror that a monk of the year one thousand spoke of the devil. »
However, traitors have crept into the international brigades. In the midst of the Battle of Madrid, we discover that the Belgian officer in command of the artillery has sabotaged his guns and tried to join the Francoists. He is a member of "Rex", the pro-Nazi party of Léon Degrelle. He is shot.