Both Carranza and Huerta regarded this move as equivalent to an act of war. Argentina, Brazil, and Chile then offered their mediation. But the conference arranged for this purpose at Niagara Falls, Canada, had before it a task altogether impossible of accomplishment. Though Carranza was willing to have the Constitutionalists represented, if the discussion related solely to the immediate issue between the United States and Huerta, he declined to extend the scope of the conference so as to admit the right of the United States to interfere in the internal affairs of Mexico. The conference accomplished nothing so far as the immediate issue was concerned. The dictator did not make reparation for the "affronts and indignities" he had committed; but his day was over. The advance of the Constitutionalists southward compelled him in July to abandon the capital and leave the country. Four months later the American forces were withdrawn from Vera Cruz. The "A B C" Conference, however barren it was of direct results, helped to allay suspicions of the United States in Hispanic America and brought appreciably nearer a "concert of the western world." While far from exercising full control throughout Mexico, the "first chief" of the Constitutionalists was easily the dominant figure in the situation. At home a ranchman, in public affairs a statesman of considerable ability, knowing how to insist and yet how to temporize, Carranza carried on a struggle, both in arms and in diplomacy, which singled him out as a remarkable character. Shrewdly aware of the advantageous circumstances afforded him by the war in Europe, he turned them to account with a degree of skill that blocked every attempt at defeat or compromise. No matter how serious the opposition to him in Mexico itself, how menacing the attitude of the United States, or how persuasive the conciliatory disposition of Hispanic American nations, he clung stubbornly and tenaciously to his program. Even after Huerta had been eliminated, Carranza's position was not assured, for Francisco, or "Pancho," Villa, a chieftain whose personal qualities resembled those of the fallen dictator, was equally determined to eliminate him. For a brief moment, indeed, peace reigned. Under an alleged agreement between them, a convention of Constitutionalist officers was to choose a provisional President, who should be ineligible as a candidate for the permanent presidency at the regular elections. When Carranza assumed both of these positions, Villa declared his act a violation of their understanding and insisted upon his retirement. Inasmuch as the convention was dominated by Villa, the "first chief" decided to ignore its election of a provisional President.