How we cite our quotes: (Sentence)
Quote #1
[…] 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's using the United States' revolutionary history as a reason for why there shouldn't be more colonies. Correction: why there can't be more colonies. He's pretty clear new colonies are no longer an option.
Quote #2
In the wars of the European powers in matters relating to themselves we have never taken any part, nor does it comport with our policy to do so. It is only when our rights are invaded or seriously menaced that we resent injuries or make preparation for our defense. (9-10)
Although the Monroe Doctrine is a strong statement asserting American influence, the president also knows not to ignore the reality of European power, or present the U.S. as just another version of those Old World imperialists. They're just defending themselves, guys.
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, on great consideration and on just principles, 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)
The heart of the Monroe Doctrine both takes away power from Europe, but also declares America as a new force to be reckoned with. The statement is both paternalistic (treating Latin America like a child) and defensive. Now the whole western hemisphere is connected to the U.S.
Quote #4
Our policy in regard to Europe, which was adopted at an early stage of the wars which have so long agitated that quarter of the globe, nevertheless remains the same, which is, not to interfere in the internal concerns of any of its powers; to consider the government de facto as the legitimate government for us; to cultivate friendly relations with it, and to preserve those relations by a frank, firm, and manly policy, meeting in all instances the just claims of every power, submitting to injuries from none. (21)
Monroe includes a kind of a sly insult here. It's like saying, "Hey, we've been nice this whole time. We've been happy to deal with whoever's in power during your unending warfare." He uses the power struggles that have been happening over many decades in Europe to boost the image of the U.S.
Quote #5
It is equally impossible, therefore, that we should behold such interposition in any form with indifference. If we look to the comparative strength and resources of Spain and those new Governments, and their distance from each other, it must be obvious that she can never subdue them. (24-25)
At the end of the Monroe Doctrine, the president makes the argument that re-taking the Latin American colonies would just be logistically difficult. Spain shouldn't even bother, because they're no longer powerful enough to do it. Seriously Spain: it's not worth the trouble.