Take chronic complaints that the Japanese are getting a "free ride" on the back of heavy American military commitments.

Add the inside maneuvering of Japan's powerful bureaucrats operating in a system in which they have to be steered -- rather than ordered -- toward an objective.

Top it off with Prime Minister Zenko Suzuki's desire to accommodate the Americans and the problems of communication between literal-minded American officials and more verbally oblique Japanese.

What you get is Washington's perception that Japan would increase its 1981 defense budget by 9.7 percent, Japan's announcement that the figure actually will be 7.6 percent, an infuriated Carter administration charging that Japan was shirking its responsibilities and a flash point for conflict with the new Reagan administration.

To be sure, defense remains a very emotional issue in the land of Hiroshima and Nagasaki and foreign observers tend to interpret Tokyo's yen pinching as the outcome of a clash of ideologies between pacifists on the nation's political left and ultranationalists on the right.

But the recent hotly debated defense decision her reflects a fundamental struggle among Japan's competing government departments to protect their bureaucratic fiedoms from cuts under Tokyo's new fiscal austerity program.

Above all, its outcome shows that the best the prime minister can expect to do -- in the anonymous style of Japan's leaders -- is to mold the policy preferences of his bureaucratic subordinates and steer them toward a final decision.

Suzuki gave a hit of Japan's complicated governmental procedure when he gave an unsolicited fishing tip to then-U.S. defense secretary Harold Brown during Brown's visit here last December.

"When you're trying to land a big fish," Japan's unassuming leader told Brown, who was pressing him to boost military spending, "you've got to be patient, feed it a little line, then pull it in slowly and carefully." He was presumably talking about getting his government to do what Washington believed Japan had promised to do months earlier -- boost defense spending by at least 9.7 percent.

On the surface, Suzuki appeared to have the political mandate needed to deliver on the pledge made by his predecessor, the late Masayoshi Ohira, during White House tgalks with former president Carter. Ohira's pledge had been that Japan would made "steady and significant" increases in defense spending in the years ahead. But despite the fact that Suzuki rode into office last July on the wave of the Liberal Democrats' landslide election victory, the new premier soon found himself squeezed by the constraints of Ohira's double political legacy: to raise defense spending and, at the same time, cut back on Tokyo's $365 billion deficit.

Among his fellow Liberal Democrats, who have kept the country under their conservative sway for the last 25 years, Suzuki's skills for striking political compromise on touchy public issues is legendary. Such acumen allowed Suzuki to steer his Cabinet to a decision, unprecedented for a postwar Japanese leader, to put a priority on defense spending in the making of the 1981 national budget beyond the more austere limits placed on practically all other government departments.

Mindful of Pentagon officials' complaint that the resulting 9.7 percent defense ceiling was still too low, Suzuki, in another deft maneuver, negotiated an agreement between Finance Minister Michio Watanabe and Defense Agency Director Gen. Joji Omura that further appropriatiions would be considered if changes in the international scene warranted them before the budget draft came up for final Cabinet approval in late December.

This "oral understanding" led American officials to believe that the final defense figure could climb to near 14 percent once futher negotiated increases and a 2.2 percent military pay increase were added in.

In Japan's consensus-seeking society, stress is placed on avoiding public confrontation while a decision is being hammered out between contending parties. The end result carries the force of majority opinion but shows meticulous concern for minority views.

Ironically, just as Suzuki appeared to have successfully squared the political circle by compromising American demands with domestic priorities, his consensus began to evaporate.

In his eagerness to avert a showdown with Washington, Suzuki committed the cardinal error for a Japanese leader of failing to square defense commitments in advance with the powers and prerogatives of Japan's elite senior bureaucrats.

Unlike an American president's White House staff, Japanese prime ministers are severly limited in their policymaking prerogatives by the absence of a large retinue of appointed advisers.

In Japan, practically all important decisions on public policy are made by, and largely at the discretion of, the nation's senior career bureaucrats. Restricted by the lack of large legislative staffs that allow U.S. politicians more initiative, Japanese legislators are largely at the mercy of the administrators who provide policy briefings, draft the bulk of legislation and act on bills once they become law.

"There is no national government," goes a well-known political axion here, "there are only the individual ministries." The key decisions on defense, as on other budget issues, were made, in the unobtrusive style of Japanese bureaucrats, after vigorous debate by senior department heads far from public view. The outcome was the result of a knockdown, dragout battle, according to rigidly hierarchical rules, and not the exquisitely polite process that foreigners often imagine.

The traditionally tight-fisted Finance Ministry sits on the top of Japan's bureaucratic pecking order. Burdened with deficts amounting to nearly one-third of the country's gross national product, finance officials whittled away at Suzuki's priority proposals on military spending with a vengeance. The equally powerful Ministry of International Trade and Industry, anxious to protect appropriations for public works spending in 1981 that aid its bureaucratic sphere among Japanese industry, raised strong objections.

In the ministry's view, steps toward an enlarged defense budget, and the stronger foreign policy stance that implies, could threaten Japan's omnidirectional diplomacy that has in the past allowed it to trade freely with countries regardless of their politics.

Even within the internationally minded Foreign Minstry, there is strong sentiment for expanding the definition of defense to include increases in the budget for foreign economic aid designed to bolster the stability of governments of special strategic importance to Tokyo, especially those close to home in the five-nation Association of Southeast Asian Naions. More money for defense could conceivably mean less for these programs in the 1980s.

The Japan Defense Agency, hampered by three decades of Tokyo's "peace diplomacy" and antiwar public opinion, occupies the bottom rung in the bureaucratic hierarchy. Defense officials vainly argued for defense spending hikes that would allow Japan to build a more effective deterent to what they described as a rapidly expanding Soviet military threat in the Western Pacific.

Taking the unusual step for an officer of questioning government policies, Gen. Goro Takeda, chairman of the Joint Chief of Staff Council, publicly called for a threefold increase in the military budget and challeneged the official doctrine that a draft would be unconstitutional. In a recent interview he also questioned the doctrine that the country's armed forces cannot be used abroad even as a way of defending Japan.

But Defense Agency officials suffered from the fact that, to the affluent Japanese, the bread-and-butter issues of improved housing and social services outflank what they consider the more abstract issues of defense. They were also hurt by rumors that the Defense Agency was encouraging U.S. pressure on Tokyo to help force through more defense funds.

Government departments here rely on career bureaucrats for advice on how far and in what form they can expect to push specific legislative proposals. But the latest defense decision also reflects what can happen when the bureaucratic tail starts wagging tghe political dog as it appears to have done in the case of two key Cabinet ministers.

Finance Minister Watanabe, widely known for his hawkish stand on defense when he was appointed to his post last July, was quickly forced to surrender his personal preferences to meet the more parochial priorities of his austerity-minded subordinates. Welfare Minister Sunao Sonoda, who is said to privately favor a more effective defensive stance for Japan -- and who as two-term foreign minister under Ohira displayed a detailed grasp of global issues -- also ran into a wall of resistance from his bureaucratic charges. Sonoda threatened to resign his post should the increase in defense spending be allowed to outstrip that for welfare.

Suzuki managed to maneuver his ministers into a final compromise: the Finance Ministry grudgingly agreed to drop its demand that defense spending be restricted to a 6.6 percent increase in 1981 and the resulting figure of 7.61 percent was so close to the Welfare Ministry's flat 7.6 percent hike as to avert Sonoda's threatened resignation.

But there is no question that Japan's 7.6 percent solution is far below what officials in Washington had been led to expect.