The primary responsibility for the Japanese foreign policy, as determined by the 1947 constitution, is exercised by the cabinet and subject to the overall supervision of the National Diet.
[7] Constitutionally since 1945 the dominant figure in the political system, the prime minister has the final word in major foreign policy decisions.
[8] When Japan regained its sovereignty in 1952 and reentered the international community as an independent nation, it found itself in a world preoccupied by the Cold War between East and West, in which the Soviet Union and the United States headed opposing camps.
Japan's foreign policy goals during most of the early postwar period were essentially to regain economic viability and establish its credibility as a peaceful member of the world community.
A special diplomatic task was to assuage the suspicions and alleviate the resentments of Asian neighbors who had suffered from Japanese colonial rule and imperialist aggression in the past.
Under its unidirectional diplomacy, it sought to cultivate friendly ties with all nations, proclaimed a policy of "separation of politics and economics," and adhered to a neutral position on some east–west issues.
In the 1970s, the basic postwar principles remained unchanged but were approached from a new perspective, owing to the pressure of practical politics at home and abroad.
There was growing domestic pressure on the government to exercise more foreign policy initiatives independent of the United States, without, however, compromising vital security and economic ties.
Changes in the power relationships in the Asia-Pacific quadrilateral—made up of Japan, the People's Republic of China, the United States, and the Soviet Union—also called for reexamination of policies.
The deepening Sino-Soviet split and confrontation, the dramatic rapprochement between the United States and China, the rapid reduction of the United States military presence in Asia following the Vietnam War (Second Indochina War, 1954–75), and the 1970s expansion of Soviet military power in the western Pacific all required a reevaluation of Japan's security position and overall role in Asia.
But the oil crises of the 1970s sharpened Japanese awareness of the country's vulnerability to cutoffs of raw material and energy supplies, underscoring the need for a less passive, more independent foreign policy.
Thus, political leaders began to argue that in the interests of economic self-preservation, more attention should be paid to the financial and development needs of other countries, especially those that provided Japan with vital energy and raw material supplies.
The differences in outlook between the older leaders still in positions of power and influence and the younger generation that was replacing them complicated formulation of foreign policy.
Japan became the world's largest creditor, an increasingly active investor in the United States, and a major contributor to international debt relief, financial institutions, and other assistance efforts.
By 1990 Japan's foreign policy choices often challenged the leadership's tendency to avoid radical shifts and to rely on incremental adjustments.
Inside Japan, both elite and popular opinion expressed growing support for a more prominent international role, proportionate to the nation's economic power, foreign assistance, trade, and investment.
The collapse of communism in Eastern Europe and the widely publicized brutalities of communist regimes in Asia in the late 1980s further dampened popular Japanese interest in shifting foreign policy to the left.
The Sino-United States rapprochement of the 1970s and the stiffening of Japan-Soviet relations in the 1980s caused the opposition parties to be less insistent on the need to terminate the security treaty.
The social composition of LDP support shifted away from the traditional conservative reliance on business and rural groups to include every category of the electorate.
The LDP had brought together various candidates and their supporting interest groups and had reached a policy consensus to pursue economic development while depending strongly on the United States security umbrella.
Some of the opposing elements included were leftists who sought to exert influence through their representatives in the Diet, through mass organizations, and sometimes through rallies and street demonstrations.
Broadly stated, the partisan disagreement among the various groups competing for power had centered on the question of Japan's safety from external threat or attack.
The dominant view was that although the Japanese should be responsible for defending their homeland, they should also continue their security ties with the United States, at least until they could gain sufficient confidence in their own self-defense power, which has been interpreted as not being proscribed by Article 9 of the constitution.
Proponents of this view agreed that this self-defense capability should be based on conventional arms and that any nuclear shield should be provided by the United States under the 1960 security treaty.
These shared views stemmed from the resurgence of nationalism during the post–World War II era and from the pride of the Japanese people in their own heritage and in the economic achievements of the postwar decades.
Except for security-related matters, most foreign affairs issues involved economic interests and mainly attracted the attention of the specific groups affected.
Because trade and capital investment issues were involved, for example, in relations with the People's Republic of China and with South Korea, the business community increasingly became an interested party in the conduct of foreign affairs.
Similarly, when fishing rights or agricultural imports were being negotiated, representatives of the industries affected worked with political leaders and the foreign affairs bureaucracies in shaping policy.
This situation meant that significant debate and deliberations on foreign policy matters generally took place not in the Diet but in closed-door meetings of the governing LDP.
Among the major catalysts were a shift in Japan's national security objectives, and widespread criticism of its “checkbook diplomacy” policy during the first Gulf War.