What was the purpose of the Monroe Doctrine?
O It was a treaty for the United States to buy land.
O It increased trade with other nations in Europe and Asia.
It warned European nations to stay away from Western nations.
It was a policy to increase the size of the U. S. military.

Right choice is:

It warned European nations to stay away from Western nations.

Explanation:

The Monroe Doctrine is a concept that sees any intervention of extrarregional powers (mainly of Europe in 1823) in the affairs of the nations of the Western Hemisphere as a threat to the United States´ security. It also states that the US would not intervene in the conflicts or issues of the European powers.

- "schenck v. united states, case in which the u.s. supreme court ruled on march 3, 1919, that the freedom of speech protection afforded in the u.s. constitution's first amendment could be restricted if the words spoken or printed represented to society a “clear and present danger.” "

- speech aimed to potentially create danger could be banned.

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