Some historians might argue that the United States should have been a more progressive country in the early twentieth century, as domestically, many Presidents were moving towards a more progressive agenda. For example, Theodore Roosevelt used the Sherman Anti-Trust Act to break apart monopolies and instituted federal legislation such as the Hepburn Railroad Act and Pure Food and Drug Act to make railroad rates fairer and to regulate the quality of food and drugs, respectively.
However, internationally, Roosevelt's agenda was one of enforcing American imperialism on other countries. In 1898 (slightly before the period in the question), Roosevelt, then Assistant Secretary of the Navy, ordered Admiral Dewey to attack the Philippines if war broke out between Spain the United States (which happened after the explosion of the U.S. battleship the Maine in Havana harbor). This was the outbreak of the Spanish-American War, which led the U.S. to institute the Platt Amendment in Cuba. This legislation restricted Cuba's ability to make agreements with other countries and allowed the U.S. to intervene in Cuba's domestic affairs. Later, Teddy Roosevelt fomented a revolution in Colombia so that Panama would break away from Colombia. This revolution facilitated Roosevelt's building of the Panama Canal. His idea was to facilitate shipping from one coast of the U.S. to the other.
During the Taft administration, the U.S. pursued a policy of "dollar diplomacy" that promoted American investment abroad, particularly in Latin America and the Far East. It was not until Wilson's entry into World War I in 1917 that the U.S. supported a policy that, at least on the surface, was aimed at promoting international diplomacy and world peace. Until that time, the U.S. pursued an imperialist agenda that was aimed at aiding the American economy and facilitating American conquests abroad.
The U.S. should have taken a more progressive moral stance that provided assistance in the form of financial aid and technical knowledge to countries that were struggling to feed themselves, such as Cuba. This type of humanitarian aid would have provided greater stability than the constant military interventions conducted by the U.S. If the U.S. choose to intervene in a country such as Panama to build infrastructure that would benefit Americans, the American government could have also provided local assistance, such as setting up healthcare clinics or working to eradicate disease-carrying insects. The U.S. should have been a moral example rather than an unfettered interventionist.