Truman Doctrine
Summary: Truman's speech before the joint assembly of Congress that established the following Truman Doctrine was actually in specific reference to two specific nations: Greece and Turkey. Both states were in dire need of economic assistance, and had reached out to the US hoping to receive it. Truman called upon Congress to help these nations, and any others like them, with political, military, and economic aid - else he warned they might fall victim to more authoritarian or Communist power. The President saw this expansion of US influence as the only viable tactic to peacefully combat the rising tide of Communism, and considered the costs of following it a "small price to protect our WWII investment into peace and freedom."
(Similarly to Truman's era, nowadays American leaders from both sides of politics have utilized financial and military aide to "prop-up" pro-democracy or pro-American leadership in nations that might otherwise succumb to rule by authoritarians or terrorists).