Which President proposed the "New Nationalism" that included a strong foreign policy to advance U.S. interests?

The correct answer is Theodore Roosevelt, who proposed the "New Nationalism" platform during the early 20th century. This concept was primarily focused on domestic reform but also emphasized a strong and assertive foreign policy that aimed to enhance American influence on the global stage. Roosevelt believed that the United States should actively engage with the world and take a leading role in international affairs. His approach included the idea of using American power to support not only economic interests but also to promote stability in other nations, particularly in Latin America.

The doctrine was also reflected in his implementation of policies such as the Roosevelt Corollary to the Monroe Doctrine, which justified U.S. intervention in the Western Hemisphere if nations were deemed unable to maintain order or pay debts. This stance illustrated his belief in using military and diplomatic power to protect U.S. interests abroad, showcasing how "New Nationalism" intertwined domestic reform with a vigorous foreign policy.