The Soviet Union and to a lesser extend France and Mexico
Explanation:
Francisco Franco led the Nationalist party and was assisted by Hitler's Germany and Mussolini's Italy. While the Republicans (Loyalists) fought against Francisco Franco's Facist government. The Republican's, due to neutrality laws of other world powers at the time, bought Soviet Union weapons, munitions, and equipment. Soviet Union soldiers and tanks even volunteered and fought against Francisco Franco.
