It was while the United States was thus widening the sphere of its influence in the Caribbean that the "A B C" powers--Argentina, Brazil, and Chile--reached an understanding which was in a sense a measure of self-defense. For some years cordial relations had existed among these three nations which had grown so remarkably in strength and prestige. It was felt that by united action they might set up in the New World the European principle of a balance of power, assume the leadership in Hispanic America, and serve in some degree as a counterpoise to the United States. Nevertheless they were disposed to cooperate with their northern neighbor in the peaceable adjustment of conflicts in which other Hispanic countries were concerned, provided that the mediation carried on by such a "concert of the western world" did not include actual intervention in the internal affairs of the countries involved. With this attitude of the public mind, it is not strange that the Hispanic republics at large should have been inclined to look with scant favor upon proposals made by the United States, in 1916, to render the spirit of Pan-Americanism more precise in its operation. The proposals in substance were these: that all the nations of America "mutually agree to guarantee the territorial integrity" of one another; to "maintain a republican form of government"; to prohibit the "exportation of arms to any but the legally constituted governments"; and to adopt laws of neutrality which would make it "impossible to filibustering expeditions to threaten or carry on revolutions in neighboring republics." These proposals appear to have received no formal approval beyond what is signified by the diplomatic expression "in principle." Considering the disparity in strength, wealth, and prestige between the northern country and its southern fellows, suggestions of the sort could be made practicable only by letting the United States do whatever it might think needful to accomplish the objects which it sought. Obviously the Hispanic nations, singly or collectively, would hardly venture to take any such action within the borders of the United States itself, if, for example, it failed to maintain what, in their opinion, was "a republican form of government." A full acceptance of the plan accordingly would have amounted to a recognition of American overlordship, and this they were naturally not disposed to admit.