In the very first year of the Hay-Bunau-Varilla Treaty, dissension had already arisen over the sovereignty issue. Acting on an understanding of its rights, the United States had applied special regulations to maritime traffic at the ports of entry to the canal and had established its own customs, tariffs, and postal services in the zone. These measures were opposed by the Panamanian government.

Mounting friction finally led Roosevelt to dispatch Secretary of War William Howard Taft to Panama in November 1904. His visit resulted in a compromise agreement, whereby the United States retained control of the ports of Ancón and Cristóbal, but their facilities might be used by any ships entering Panama City and Colón. The agreement also involved a reciprocal reduction of tariffs and the free passage of persons and goods from the Canal Zone into the republic. Compromises were reached in other areas, and both sides emerged with most of their grievances blunted if not wholly resolved.

Before the first year of independence had passed, the intervention issue also complicated relations. Threats to constitutional government in the republic by a Panamanian military leader, General Estéban Huertas, had resulted, at the suggestion of the United States diplomatic mission, in disbanding the Panamanian army in 1904. The army was replaced by the National Police, whose mission was to carry out ordinary police work. By 1920 the United States had intervened four times in the civil life of the republic. These interventions involved little military conflict and were, with one exception, at the request of one Panamanian faction or another.

The internal dynamics of Panamanian politics encouraged appeals to the United States by any currently disgruntled faction for intervention to secure its allegedly infringed rights. United States diplomatic personnel in Panama also served as advisers to Panamanian officials, a policy resented by nationalists. In 1921 the issue of intervention was formally raised by the republic's government. When asked for a definitive, written interpretation of the pertinent treaty clauses, Secretary of State Charles Evans Hughes pointed to inherent difficulties and explained that the main objectives of the United States were to act against any threat to the Canal Zone or the lives and holdings of non-Panamanians in the two major cities.

Actual intervention took several forms. United States officials supervised elections at the request of incumbent governments. To protect lives of United States citizens and property in Chiriquí Province, an occupation force was stationed there for two years over the protests of Panamanians who contended that the right of occupation could apply only to the two major cities. United States involvement in the 1925 rent riots in Panama City was also widely resented. After violent disturbances during October, and at the request of the Panamanian government, 600 troops with fixed bayonets dispersed mobs threatening to seize the city.

At the end of the 1920s, traditional United States policy toward intervention was revised. In 1928 Secretary of State Frank B. Kellogg reiterated his government's refusal to countenance illegal changes of government. In the same year, however, Washington declined to intervene during the national elections that placed Florencio H. Arosemena in office. The Arosemena government was noted for its corruption. But when a coup d'état was undertaken to unseat Arosemena, the United States once again declined to intervene. Though no official pronouncement of a shift in policy had been made, the 1931 coup d'état--the first successful one in the republic's history--marked a watershed in the history of United States intervention.

Meanwhile, popular sentiment on both sides calling for revisions to the treaty had resulted in the Kellogg-Alfaro Treaty of 1925. The United States in this instrument agreed to restrictions on private commercial operations in the Canal Zone and also agreed to a tightening of the regulations pertaining to the official commissaries. At the same time, however, the United States gained several concessions involving security. Panama agreed to automatic participation in any war involving the United States and to United States supervision and control of military operations within the republic. These and other clauses aroused strong opposition and, amid considerable tumult, the National Assembly on January 26, 1927, refused to consider the draft treaty.

The abortive Kellogg-Alfaro Treaty involved the two countries in a critical incident with the League of Nations. During the fall of 1927, the League Assembly insisted that Panama could not legally participate in the proposed arrangement with the United States. The assembly argued that an automatic declaration of war would violate Panama's obligations under the League Covenant to wait three months for an arbitral decision on any dispute before resorting to war. The discussion was largely academic inasmuch as the treaty had already been effectively rejected, but Panama proposed that the dispute over sovereignty in the Canal Zone be submitted to international arbitration. The United States denied that any issue needed arbitration.

Data as of December 1987