Alliances were an important feature of the international system on the eve of World War I. The formation of rival blocs of Great Powers has previously considered a major cause of the outbreak of war in 1914. The alliances system meant that a local conflict could easily result into an intimidating global one. Nationalism was a great cause of World War one because of countries being greedy and not negotiating.
The US had to draft soldiers to fight in the war and it had to train them to do so effectively.Businesses and citizens were strongly urged to support the war through government and media communications.
