William J. Lederer, co-author of "The Ugly American," is a man who likes to tell stories. He peppers his conversation with a frequent "That reminds me...," and puffing slowly on a handlebar pipe, he will tell you about China, Thailand, Indonesia, Vietnam, 20-odd years in the Navy, and--after a year as writer-in-residence at Kirkland House--a lot about Harvard.

He combines a Mark Twain love for reminiscences with the crustiness of a Gloucester mariner. He does not mince words when he does what he is best at and best known for -- dropping bombs on U.S. foreign policy in Asia.

Lederer is caustically critical of 20 years of State Department decision-making on Southeast Asia. He traces mistakes to inadequate information, charging that analysts in State have naively accepted reports from the heads of local governments rather than sending qualified people into the countryside to check for themselves. In countries that are populated predominantly by rural peasants, says Lederer, "our government almost invariably doesn't know enough about what is going on."

Lederer calls it "misinformation." He considers its results disastrous, particularly in simmering trouble spots like Vietnam, where "before 1954 all our information on what was happening came from the French."

As a reporter in Asia since 1958, Lederer has made it his job to get what he calls "the real facts" about the conditions in Asian countries. A copious note-taker, he follows one uncompromising principle: the truth can only be found by talking to the rank-and-file people of a country.

To have candid interviews with ordinary people, Lederer uses unconventional techniques. In Thailand, for example, he and his student interpreters go to a "noodle stand" -- an after-work social club--where, Lederer will have his palm read (an obsession among Thais) to gain peoples' trust and "to show them that you are not trying to catch them." After his palm has been read, Lederer, with the help of his students, reads palms himself and starts asking questions. "When I ask a man what he would most like to win, he may say a lottery, so that he will have some money because the Government official is stealing it all from the local treasury. Then I know there's a problem."

In 1957, Lederer walked from Hanoi to Haiphong with 2000 Vietnamese refugees who were going South after the Vietminh victory over the French. "They were old men and women carrying small children -- no young men," he says. He also learned from these refugees that "they were all Catholic, and their Priests told them God had moved to Saigon."

Lederer believes that although revolutions are organized by minorities, they can spread only if there is discontent among the rank-and-file people. Because American policy decisions are based on estimates of the stability of regimes, he says, it is crucial to have precise information on the real feelings of major groups in the population. Lederer strongly urges recruiting more area experts for the foreign service.

The archetype of Lederer's beautiful American is former U.S. Ambassador to Japan, Edwin O. Reischauer: He is perfectly at home with the Japanese and can converse with them in their own language.

One of Lederer's many stories is about the Japanese tailors who copied the clothes of the popular Ambassador, then advertised "Reischauer suits" on television. The excellent relations between the U.S. and Japan, Lederer contends, are largely due to Reischauer and the group of Japanese specialists whom he brought onto his Embassy staff.

The fact that Reischauer was an in-and-outer does not necessarily validate Lederer's basic criticism of the State Department -- that it regularly has inadequate information about Southeast Asia. Vietnam, where the U.S. has become intensely involved since 1954, is a better test.

During the Diem rule, the U.S. backed the "Strategic Hamlet Program" and tried to initiate reforms that would broaden the popular support of the Saigon government. This policy was based on reliable information about what should be done, but the U.S. has not had the ability either to check on the results of Diem's hamlet program or to insure that the Vietnamese even carried them out.

Since neither the pacification program nor the political reforms of Diem succeeded, Lederer was at least partially right in analysing American ineptitude. Although the U.S. backed worthy programs, its information on their grass-roots effectiveness was faulty.

The massive involvement in Vietnam since 1965 will force the U.S. to send people to the hamlet level to check the effectiveness of new programs. In this sense Vietnam is the test of whether Lederer's criticisms will continue to be true. Are "The Ugly American" and "A Nation of Sheep" but dated?

To answer this question Lederer has already left Harvard for a six-week tour of Vietnam and other Asian countries. In his familiar pattern, he will interview U.S. and Vietnamese officials, and the people for a new book on "The Processes of American Foreign Policy."

Even if the U.S. is becoming more aware of the rural peoples in Asia -- and that is debatable -- Lederer takes little credit for it. "I want to get the nation murmuring," he says. When pressed, he modestly concedes that some of his books spurred the creation of the Peace Corps and the Army Language School.

Lederer has sometimes found his role as foreign policy critic advantageous. Shortly after writing "A Nation of Sheep" in 1962, he dropped by the White House to visit a Kennedy aide. As Lederer tells the story, the President, carrying galley proofs of the book, emerged from his office to meet the author. The President, Lederer recalls, liked the book "and asked me if I knew what the British had done in Malaya. I said that I did, but that it would take me a few minutes to write it down. He took me to his office and sat me at his desk with a pen and paper."

Above all, Lederer is fascinated by the means of foreign policy-making. He does not simply disagree with the conduct of U.S. policy in Asia; he prefers to point out where the system has gone wrong -- in its collection of facts. He calls himself "perceptive about systems."

Unlike those who merely advocate a change in policy, Lederer believes that no change is probable until the system which determines policy has readapted itself to a new situation. His challenge to the U.S. is that it must come to terms with the vast increase in political participation by the underdeveloped masses of Southeast Asia. The fact that Lederer has voiced the challenge for years makes it no less relevant today.