"The war which the great democracies are preparing is a war of exhaustion. One must therefore start with the worst assumption which contains 100 per cent. probability. The Axis will get nothing more from the rest of the world. This assumption is hard, but the strategic positions reached by the Axis diminish considerably, the vicissitude and the danger of a war of exhaustion. For this purpose one must take the whole Danube and Balkan area immediately after the very first hours of the war. One cannot be satisfied with declarations of neutrality, but must occupy the territories and use them for the procurement of the necessary food and industrial war supplies."
Mussolini May 30th 1939
Trials of German Major War Criminals: Volume 10