Sgt. Charlie Rangel thought he had it made in November 1950. His artillery unit was in a holding position near the Chinese border, having helped the 2nd Infantry Division push the North Korean invaders completely out of the South in less than four months.

“We thought the war was over,” Rangel, the 18-term Democrat from New York City, recalled in his legendarily crusty voice on Friday. “We were waiting to go home.”

Then, without warning, the Chinese Peoples Liberation Army appeared out of the frozen air. Waves of infantry raced down from the hills, taking him and his men completely by surprise.

“It was really a nightmare. Bugles, horses, loudspeakers, tens of thousands — hordes of Chinese. . . .”

They were surrounded.

“A lot of officers escaped by helicopters, to tell you the truth,” he said, still disturbed 56 years later. “Many of our people died because they just froze to death.”

Rangel took a hit, but still managed to lead 42 of his men from behind the lines. He was awarded several medals, including a Purple Heart.

“We had no idea that the Chinese would ever got involved,” he said.

Over a half century later, the situation in North Korea is still pretty much an enigma to U.S. policy makers — and our intelligence services, some critics say.

The U.S. needs a few good spies in Pyongyang. All the planes, ships and satellites buzzing around North Korea can’t tell us what the Hermit Kingdom’s flamboyant head of state has up the sleeve of his gray tunic.

Today, experts say the CIA is almost entirely at the mercy of its South Korean ally for intelligence on the North — and they, too, were evidently surprised by the Oct. 9 nuclear test.

“We believe a lot,” former U.N. weapons inspector David Kay said to fellow participants in a war game on North Korea last year, in which he played the role of CIA director. “We actually know very little.”

Jessica Mathews, a former White House National Security Council and State Department official who played director of national intelligence in the game, agreed. “There’s very little we can say that we know with confidence, either politically or technically, about North Korea,” she was quoted telling fellow role-players by The Atlantic Monthly, which sponsored the game.

A former top Clinton administration official echoed those sentiments just last week. Wendy Sherman, Clinton’s former special adviser on North Korea, suggested in a Oct. 12 call with reporters that U.S. spy services hadn’t a clue to what Pyongyang’s leaders had on their minds. She recalled talking to a South Korean official “who had been to meet with Kim Jong Il many times in secret, had read every book in Korean about Kim Jong Il. And we all experienced the reality that much of what any intelligence community had to say was pretty ill-informed.”

Sherman, Mathews and Kay are Bush administration critics, to be sure, perhaps even Democrats. And if Iraq hadn’t already opened an unbridgeable crevasse between the parties on foreign policy, Korea is pushing them even farther apart. Here again, and aggravated by Iraq, the dearth of agreed-upon intelligence is worsening the debate, driving each side into armchair theories about how to handle the looming confrontation.

Take the basics, like taking out North Korea’s missile sites. The current debate seems to revolve only around “when” a strike would occur. And some administration hawks have suggested the U.S. Air Force could handle that with ease.

But it turns out that most of the missiles are hidden in underground bunkers, according to the participants in the March, 2005, war game, which attracted little notice beyond being written up by The Atlantic Monthly. The same with whatever other arsenals it has — nuclear, chemical or biological.

“You begin to see how difficult a target set this is,” said retired Air Force Col. Sam Gardiner, who ran the war game.

So, once again, we simply don’t know where the weapons are — the hawks and doves at the table agreed on that. But you’d hardly know from listening to administration officials, their allies on the Hill and on Fox News.

Hearing them, you’d think the debate was hardly more than picking vanilla or chocolate — bomb or blockade, now or later.

The war gamers also agreed a preemptive strike on North Korea’s nuclear facilities could well trigger a missile and artillery barrage on Seoul, the South Korean capital, population 10 million, including 100,000 Americans.

“I believe that we have the capability — whether from pre-emption or response — to minimize the casualties in Seoul,” retired Air Force Lt. Gen. Thomas McInerney asserted.

“ ‘Minimize’ to roughly what level?” Mathews asked. “A hundred thousand? Two hundred thousand?”

“I think a hundred thousand or less.”

So much for a quick pristine air victory.

The administration is also pushing an economic blockade. This scenario, too, seems detached from reality.

The war gamers and other analysts agree that either blockades, or the fairly quick destruction of North Korea’s army by U.S. air and naval forces, would lead to a collapse of the regime.

Terrific, say many observers — exactly what we want.

But wait, there’s more: Anarchy would follow, driving tens of millions of starving refugees into the south and north, to China.

No one knows what come next. Beneath the fog of war could be a pan-Asian typhoon.

But the administration also seems to rule out putting G.I. boots on the ground to take control of North Korea, which would require at least 500,000 troops, the war gamers thought.

Even President Bush’s severest critics agree it can’t be done while the U.S. is tied down in Iraq and contemplating new wars with Iran and Syria.

“It’s clear we don’t have the troops to invade,” says Rangel, who barely made it out of Korea alive six decades ago. “We can beat them. But I don’t know whether or not we have the capacity to beat the North Koreans, the Iranians and the tribes in Iraq and still hold ourselves out to be a world power. I don’t see how we can do that.”

The debate over North Korea, in short, needs to be tethered back to reality — with a string of intelligence breakthroughs.

Until then, it’s all a guessing game and TV shout fests.

“The CIA is good at stealing a memo off a prime minister’s desk,” Army Gen. William Odem, who headed the eavesdropping NSA in the 1980s, once cracked to me, “but not much else.”

But that’s exactly what the U.S. needs right now: a few good spies, inside Kim Jong Il’s office.

Jeff Stein can be reached at jstein@cq.com.