In 1801 the North was fighting, not merely to preserve American national integrity, but to prevent the formation of a state on its southern frontier which could persist only by virtue of a European alliance, and which would consequently have entangled the free republic of the Northern states in the network of irrelevant European complications.

Such would be the result of any attempt on the part of the European states to seek alliances or to pursue an aggressive policy on this side of the Atlantic.
But it may be asked, how can European aggressions in America be opposed, even on the foregoing ground, without requiring enormous and increasing military preparations?
Would not the Monroe Doctrine, even in that modified form, involve the same practical inconsistency which has already been attached to its popular expression?
The answer is simple.
It will involve a similar inconsistency unless effective means are taken to avoid the inevitable dangers of such a challenge to Europe--unless, that is, means are taken to prevent Europe from having any just cause for intervention in South America for the purpose of protecting its own investment of men and money.

The probable necessity of such intervention is due to the treacherous and unstable political conditions prevailing on that continent; and the Monroe Doctrine, consequently, commits the United States at least to the attempt to constitute in the two Americas a stable and peaceful international system.

During the next two or three generations the European states will be too much preoccupied elsewhere to undertake or even to threaten any serious or concerted interference in South America.

During that interval, while the Monroe Doctrine remains in its present situation of being unrecognized but unchallenged, American statesmen will have their opportunity.