The European traveling salesman in these countries carries a line of goods immediately answerable to local requirements. Furthermore, the European exporter understands that the system of credits in Latin America is not the same as prevails in Europe and the United States, and he complies with their requirements. Of course, his prices are placed high enough so that he is nothing out of pocket for the seeming concessions he had made. The result is that in traveling in these countries, one meets three or four foreign "drummers" where he meets one American traveling man, in spite of their nearness to the United States. It will take years, even with the Panama Canal in operation, to overcome the disadvantage which bad business policy has placed upon the American manufacturers. If the opening of the Panama Canal spells new American commercial opportunities, it also develops a new field of international politics in which the United States must make itself the dominant factor, and in which it will have a transcendental interest. It will unquestionably give to the Monroe doctrine a new importance and render its maintenance a more urgent necessity than ever. Prior to this time the breaking down of the Monroe doctrine would have been greatly detrimental to the interests of the United States, but from this time forth the domination of the Caribbean by some other strong nation would likely prove most disastrous to American welfare. It might even lead to the loss of the canal itself, and we then would witness that great waterway transformed from a military asset of immeasureable benefit into a base of operations against us. Probably the chief danger to which the Monroe doctrine is exposed is from those countries whose rulers profit most by its enforcement. While the United States can control its own affairs in such a way as not to bring into question this doctrine, it is not so certain that the rulers of some of the Latin American nations will always do as well. In fact, some of the countries have conducted their affairs in such a way as might have involved the United States in a war with a foreign power. The knowledge that a small tropical American republic might act so as to force the United States into a critical situation has resulted in a desire on the part of the responsible authorities at Washington to exercise over the Republics of the Caribbean such a guiding control as would serve to prevent them, through any ill-considered or irresponsible act, from exposing the United States to dangerous controversies with foreign nations.