Mussolini's decision to help the Spanish Nationalist side in the Civil War of the 1930s was mainly linked to the attitude of France, which promised military aid to the Republican side, although in the end the first foreign aircraft to enter the conflict were Italian S.81s. Fascist Italy feared the lasting installation of a Popular Front regime in Spain, which would have had the effect of strengthening the Paris-Madrid axis, while Italy was at the time diplomatically isolated as a result of the sanctions decreed by the League of Nations in responde to the invasion of Ethiopia. Moreover, Franco promised Mussolini, through Luccardi, the establishment of a fascist republic and a clear diplomatic rapprochement in case of a nationalist victory, an argument not to be underestimated as Spain was a key country for Italian policy in the Mediterranean.