The Korean War ended 37 years ago. But a six-hour PBS documentary, "Korea: The Unknown War," has touched off a new battle even before the start of the series' three-night run tonight (8 p.m., Ch. 7).

Retired Army Gen. R.G. Stilwell, a regimental commander during the war and 20 years later the commander of United Nations forces in South Korea, thinks it is a "revisionist" account favoring North Korea and China.Not so, says Jon Halliday, a British writer who did the documentary for Thames Television, a British commercial network that undertook the project as a co-production with Boston public TV station WGBH.

"I think we'll catch flak from both the left and the right," says WGBH executive producer Austin Hoyt, who says he shot new interviews and rewrote some portions of the show to create a more balanced account.

The show's U.S. version, narrated by an American, includes interviews with North Korean officers who fought in the war and North Korean civilians.

The show revives old controversies about the war, including the charges of North Korea, which invaded the South with troops and tanks in June 1950, that South Korea started the conflict.

It also re-examines - and in the WGBH version, generally rebuffs - the communist side's accusation that the United States waged germ warfare in North Korea, charges sharply denied by the United States.

But the show is not solely about the three years of combat in which military casualties on both sides came close to 2.4 million, including 33,629 U.S. combat dead.

It also offers views - Korean, Soviet, and American - of the forces that led to the establishment of North and South Korea when Korea was divided at the 38th Parallel after World War II.

It also looks at the rise to power of Syngman Rhee in the South and Kim Il Sung in the North, the harsh life under their regimes, and what the North and South have become in the years following the armed truce that ended the war.

The origins of the series, Hoyt says, "were really sort of a revisionist view" by Halliday and Bruce Cumings. The latter is a Chicago-based history professor with whom Halliday wrote a book on the war. He is among those interviewed in the series.

"I think they made a very good contribution to see the Korean War in the context of Korea," Hoyt said.

"But there were a lot of battles at Thames between the official British military historians and Cumings and Halliday over who was responsible for the war, and whether the United States presence was a destructive one."

Hoyt asked Stilwell to look at the series and offer comments, and initially he was listed as a consultant on the WGHB version. He later asked that his name and those of two colleagues be deleted. The request was granted.

The general said he basically objects to the series because he considers it tilted toward the North Korean and Chinese viewpoint:

"I think they've (the show's makers) shown great cynicism about the American effort to come to the aid of a nation under siege and stay the course and secure the freedom of that country," he said.

The show doesn't favor the communist side, Halliday said by phone from London. In fact, he said, the Chinese "refused to cooperate with us" in the making of the series.

His goal "was to make it as objective as possible," he said. "That is, you have to listen to the voices of the competing parties. But it's absolutely not pro-North Korean or pro-communist."

His assessment of Hoyt's version of the series: "I think there is a tilt towards what I would call sort of the official U.S. position."

All is well between Hoyt and Thames officials, according to Hoyt, who says they have backed and are pleased with his changes. He's philosophical about the war over the documentary:

"The fur is flying from both the left and the right. Frankly, Gen. Stilwell thinks we didn't do enough to temper the revisionist views of Halliday and Cumings, and Halliday and Cumings think I'm in bed with Gen. Stilwell."