Explanation: In the Spanish Civil War in the mid-1930s, the two major fascist regimes of the period - Fascist Italy and Nazi Germany - got involved on the side of the Nationalists, and the Stalinist USSR got involved on the side of the leftist Republicans (not always helpfully, as seen in the insistence on purging anarchist allies). All three refrained from 'outright' war, instead opting to supply equipment and 'advisers', hoping that it would be enough to tip the scales in favor of their chosen side.
Ultimately, the nationalists won, ushering in a period of some ~40 years of fascist rule, ending only with the death of the dictator Francisco Franco.