Axis Vs. Allies
Economy
At the beginning of World War II, the Allies had a clearly superior economy to the Axis (at that time Germany) and a much greater population. Hitler's economy was falling apart, because of his aggressive rearmament techniques and he needed to grab more workers and industrial power.
Military
The strength of the Axis lay in their advanced military, modern tactics, and patriotic fervor. Hitler had recognized that organized units of planes and tanks could be used to break through defensive lines and significantly demoralize the enemy. The Allies believed that the next world war would be fought along the same lines as the previous (i.e. highly defensive trench warfare with cautious advances). Thus, they developed advanced fortifications (including the Maginot Line) and neglected their tanks and aircraft. When the war started, Great Britain had no tanks and only two aircraft designs (the Spitfire and the Hurricane) in the works and France had sparse groups of tanks spread out through the infantry. On the other hand, Germany had six armored Panzer tank divisions at the beginning of the war and an extensive air force, the Luftwaffe.