What said that it was the responsibility of the United States to help free countries from being taken over by communism

Dwight Eisenhower was the first president to describe the domino theory in which if one country fall for communism the countries near to it will fall too during the cold war

Explanation:

He was afraid that if South Vietnam fall in the Vietnam War then the neighbors countries will follow in a domino effect that it why the United States got involved in the Vietnam War because the president believed that it was their duty  to stop the spread of communism.

on november 6 and 7, 1917 (or october 24 and 25 on the julian calendar, which is why the event is often referred to as the october revolution), leftist revolutionaries led by bolshevik party leader vladimir lenin launched a nearly bloodless coup d'état against the duma's provisional government.

an explanatory essay explains something and an argumentative essay argues for or against something. hope this : )