... 1957, signed into U.S. law was "the Eisenhower Doctrine." President Dwight D. Eisenhower (left) proclaimed, in signing a congressional resolution embodying the doctrine he'd announced 3 months earlier, that the law constituted
'a further demonstration of the will of the American people to preserve peace and freedom in the world.'
Specifically, as reported by The New York Times, the resolution "establish[ed] a policy of United States resistance to Communist aggression in that strategic oil-rich area" of the world known as the Middle East. According to the State Department's website, the 1st "real test" of the doctrine came a year later when, on request of the Lebanese government, Eisenhower sent U.S. troops to Lebanon "as a signal to the Soviet Union that it would act to protect its interests in the Middle East."
(Prior March 9 posts are here, here, and here)