How we cite our quotes: (Sentence)
Quote #1
In the discussions to which this interest has given […] the occasion has been judged proper for asserting, as a principle in which the rights and interests of the United States are involved, that the American continents, by the free and independent condition which they have assumed and maintain, are henceforth not to be considered as subjects for future colonization by any European powers…(4)
Monroe is very clearly and directly trying to put a stop to European colonization across the entire New World; at least, in all the areas that have achieved independence. Why does he think the U.S. has the right or authority to make such a declaration?
Quote #2
It was stated at the commencement of the last session that a great effort was then making in Spain and Portugal to improve the condition of the people of those countries, and that it appeared to be conducted with extraordinary moderation. It need scarcely be remarked that the results have been so far very different from what was then anticipated. (5-6)
Part of Monroe's strategy is to discredit European authority by proving their, well, incompetence. Spain's attempts at liberal reform did not go well, which doesn't speak highly of that country's right to govern more colonies. Remember, at this point lots of people thought Spain was plotting to re-take some of its former territories.
Quote #3
With the existing colonies or dependencies of any European power we have not interfered and shall not interfere. But with the Governments who have declared their independence and maintain it, and whose independence we have […] acknowledged, we could not view any interposition for the purpose of oppressing them, or controlling in any other manner their destiny, by any European power in any other light than as the manifestation of an unfriendly disposition toward the United States. (15-16)
Monroe's anti-imperialist statements are strong, but not aggressive. Just because the U.S. is against further colonization doesn't mean they're going to kick the Europeans out (probably because they knew they physically couldn't). Why do you think Monroe links interference with former Latin American colonies with hostility towards the U.S.?