ベトナム戦争をめぐる米比関係

―非対称同盟と「力のパラドックス」―

抄録

During the Vietnam War, the Philippines received increased economic and military aid from the United States, and the two countries revised their base treaty twice. The United States, a major power in asymmetrical alliances, offered concessions to President Ferdinand Marcos of the Philippines, a collaborative leader of a subordinate state, in exchange for the Philippines’ participation in the war. However, Marcos withdrew the Philippines’ forces from Vietnam within only three years. According to U.S. Admiral Arthur Radford, Marcos and his government were “the world’s most accomplished thieves.” What caused this paradox of power in U.S.–Philippine relations in the 1960s?

This study identifies three elements to account for the paradox: collaborators’ strategic importance, the trustworthiness of collaborators for major powers, and the stability of collaborators. In asymmetrical alliances, a major power offers security guarantees and economic benefits to subordinate states in exchange for their cooperation. The strategic importance of the Philippines’ participation in the war, which materialized as the Philippine Civic Action Group (PHILCAG), provided U.S. officials with incentives to offer concessions to Marcos.

However, during the presidency of Diosdado Macapagal, Marcos’ predecessor, U.S. officials had rejected an increase in aid due to their mistrust of Macapagal—even though he offered to send Filipino troops to Vietnam. A major power in asymmetrical alliances will not reward collaborators if they do not have the intention or capability to fulfill their promises. On the other hand, Marcos was regarded as a capable and pro-American collaborator, especially in 1966, the first year of his presidency. U.S. officials’ trust of Marcos led them to expect his reciprocal cooperation and therefore gave them incentives to invest in helping him.

The collaborators’ cooperation with U.S. policy sometimes triggers jeopardy in domestic politics. After 1967, domestic Filipino protests restrained Marcos from cooperating with the United States, which negatively affected U.S. officials’ trust in him. Marcos, in response to the domestic pressure, decided to reduce the number of PHILCAG soldiers in 1968 and finally had the PHILCAG retreat in 1969. U.S. officials criticized those decisions and required Marcos to reconsider them, but those U.S. efforts led to nothing. By the late 1960s, there was neither cooperation from Marcos nor U.S. trust in him.

Nevertheless, the United States finally tolerated Marcos’ disobedience and continued to support him. This shows a dilemma among American policy makers: how to get their desired policy results while mitigating protests in allies’ domestic politics. Beginning in mid-1968, Filipinos developed an anti-American and anti-Marcos sentiment, which put the interests of both Marcos and the U.S. in danger. Marcos, who at least guaranteed U.S. military bases in the Philippines under these circumstances, was a useful collaborator for the United States as a result.