TOKYO, OCT. 16 -- Leading his country down a path that many Japanese seem reluctant to follow, Prime Minister Toshiki Kaifu today proposed legislation permitting him to dispatch support troops to the Persian Gulf in what would be the first foreign deployment of Japanese forces since the end of World War II.

Kaifu's bill, approved by his cabinet this morning and then formally presented to a special session of the Diet, Japan's parliament, would set up a so-called United Nations Peace Cooperation Corps to provide non-combat aid to the U.S.-led multinational force that has gathered on the Arabian Peninsula since Iraq's Aug. 2 invasion of Kuwait.

Numbering about 1,000 members, Japan's personnel commitment would be relatively small compared to those of the United States and several other countries allied against Iraqi President Saddam Hussein. But passage of the bill would constitute a historic change in the essentially isolationist foreign policy Japan has followed for nearly half a century.

Prodded by President Bush and other Western leaders, Kaifu has told the Japanese people that Japan's status as a world economic power leaves it no choice but to take an active role in global politics as well.

In addition, Japan imports more than 99 percent of the oil burned by its manufacturing sector, and about 70 percent comes from the Persian Gulf region.

For that reason, Japan has been under intense pressure from its Western allies to provide manpower in addition to the $4 billion pledged last month to support the military effort in the gulf and the Middle East nations hit hardest by a U.N. trade embargo against Iraq. "We have heard voices everywhere saying it is not sufficient just to send money," Kaifu argued.

But opinion polls show that most Japanese disagree. Recent polls have shown margins ranging from 2 to 1 to 4 to 1 against sending any Japanese forces to the Middle East.

Kaifu's bill would authorize creation of a force drawn from existing military units and from civilian volunteers. It would permit strictly noncombat activities -- driving trucks, repairing equipment and the like, but it would also authorize the Japanese troops to carry light weapons for self-defense, a provision that drew fire from opposition parties as debate opened in the Diet this afternoon.

Kaifu probably could not muster enough votes in the Diet to amend Japan's popular postwar "peace constitution," which explicitly bans the exercise of military force. Instead, he has proposed legislation that he said is consistent with the constitution because it refers to the overseas deployment of noncombat forces as an act of "collective security" rather than one of unconstitutional "collective self-defense."

It is not clear whether Kaifu can win passage of his proposal before the special legislative session ends in early November. Kaifu's Liberal Democratic Party -- despite its name, the most conservative of Japan's major parties -- has a solid majority in the Diet's lower house. But the plan could be defeated in the upper house if all opposition parties line up against it.

While Kaifu's proposal may win support from the West, it poses problems for Japan among its East Asian neighbors, many of which were invaded by the Japanese during this century. Many East Asian governments have voiced opposition to deployment of Japanese troops anywhere and fears that the creation of the Peace Cooperation Corps might be a first step toward renewed military adventures.

Kaifu has insisted that such fears are groundless because of Japan's dedication to peace. But he has conceded that "we did not have time to explain this plan fully to the Asian nations."

The debate over the bill is being played out against a backdrop of furious political maneuvering within Kaifu's party.

The prime minister is fairly openly despised by some powerful Liberal Democrats, and political maneuvering is already underway among party heavyweights hoping to replace him in the nation's top job in next year's election. Those opponents might benefit from the defeat of Kaifu's effort to reverse Japan's insular foreign policy.

Another factor that could determine the fate of Kaifu's gulf policy is Japan's relationship with the United States. Kaifu's popularity largely has been attributed to the perception here that Bush deals with him as an equal partner. But since the start of the gulf crisis, Kaifu has appeared to be a decidedly junior partner, giving in each time Bush has asked for greater Japanese support.

Thus it was a setback for the prime minister today when the major newspaper Asahi Shimbun reported on the front page that Bush pushed Kaifu hard, during the two leaders' meeting in New York last month, to send Japanese troops to the gulf.