What was the main idea of the monroe doctrine 5.01

It was a warning for European countries to stop colonization in the western hemisphere.

Explanation:

Europeans kept colonizing in the western hemisphere and influencing United States affairs, which came off as a threat to the U.S. Therefore the president at the time, President Monroe, made his thoughts and feelings loud and clear to the Europeans, threatening to use force if they tried to establish a colony.

congress also has implied powers, which derive from the necessary and proper clause of the constitution and permit congress "to make all laws which shall be necessary and proper for carrying into execution the foregoing powers, and all other powers vested by this constitution in the government of the united states.