 However, his mistake in this case was a failure to mobilize that base.The businessmen believed that economic rivalries were cause of war, and that extensive trade led to an interdependent world that would make war a very expensive and useless anachronism.However, an opposing faction of American progressives, led by ex-president Theodore Roosevelt, ridiculed arbitration as foolhardy idealism, and insisted on the realism of warfare as the only solution to serious disputes.