Since the North Korean capture of the U.S. spy ship, the Pueblo, 10 years ago the United States has quietly been moving its intelligence agents back from the forward danger zones and replacing them with sophisticated machines.

In that sense, the Pueblo was part of the "last hurrah" for the type of intelligence collection that came into full flower in the Cold War after World War II.

The first targets of Cold War espionage were the Soviet Union and China, against whom the technocrats of American intelligence deployed the leftover World War II planes and ships manned with crews.

One standard technique was to send a bomber lunging at Russia, provoking Soviet radar operators on the ground to sound the alarm.If the alarm was heeded, the Soviets would turn on the equipment that directed the fire against invading bombers.

Equipment in the U.S. bomber making the feint at Russia would record those radar signals and pinpoint the locations of the ground defenses. Such electronic intelligence was considered vital to make sure American bombers could get through Soviet defenses if war came.

Many Americans lost their lives flying the missions to provoke, or "tickle," Soviet radars. Soviet fighters often scrambled against the "invaders," sometimes shooting them down.

As the Cold War intensified, President Eisenhower worried aloud to his top associates about the possibility of another Pearl Harbor - a surprise attack on the United States because American intelligence had failed to detect a hostile nation's military buildup in time.

Eisenhower's concern gave birth to the glider-like, high-altitude U-2 spy plane. The technocrats assured the President that they had studied the Soviet Union's antiaircraft missile and concluded its fins were too small to make it accurate in the thin air where the U-2 would fly.

For a while, the Central Intelligence Agency executives running the U-2 program exulted over the results of the U-2's secret flights over Russia. From a vantage point 12 to 14 miles high, the U-2's cameras photographed Soviet military deployments on the ground.

Some of the pictures showed Mig jets vainly trying to reach the high altitude at which the intruder was flying. The antiaircraft missiles fired at the U-2 missed, just as the CIA technocrats had predicted.

However, for reasons that still are not altogether clear, a Soviet missile hit the mark on May 1, 1960, downing Francis Powers and his U-2. Soviet Prmier Nikita Khrushchev, publicly humilated by proof that he had not been able to stop the United States from spying on his country, canceled a summit meeting with Eisenhower.

The U-2 flights over the Soviet Union were stopped. The United States eventually had to settle for flying satellites over Russia to take pictures and collect electronic signals. This is still going on.

U.S. leaders also used other types of electronic intelligence collection against the Soviet Union and other nations. Submarines, their eavesdropping gear sticking above the surface of the water, for years hid close to Soviet shores, recording communications and signals.

There have been indications that a Navy officer named Lloyd M. Bucher served on one of those intelligence collection submarines, winning plaudits for evading a Soviet ship trying to force the sub to surface.

Surface ships also collected electronic intelligence. The U.S. destroyers Maddox and Turner Joy were used in tandem for this purpose. One of their missions off North Vietnam in 1964 became an international incident.

Like the bombers before them, the destroyers' job was to tickle the North Vietnamese radars into action by hostile-looking maneuvers. The Maddox had the gear for provoking fire control radars and for recording their signals.

President Johnson said that North Vietnamese torpedoe boats attacked the Maddox and Turner Joy in the Gulf of Tonkin in August, 1964, without explaining what the U.S. ships were doing. He used the incident to justify an escalation at the Vietnam war.

Although Pentagon leaders considered electronic intelligence collection by destroyers valuable, they were attracted to a proposal by Eugene Fubini: equip harmless-looking cargo ships to gather electronic intelligence. Fubini was deputy director of Pentagon research from 1963 to 1965.

Fubini felt that as long as a non-combat ship stayed in international waters it would be safe. No country would dare attack it, even if the ship were visibly forested with evesdropping gear.Navy leaders agreed.

Although the Israeli attack on the Liberty in 1967 might have given the Pentagon second thoughts about Fubini's proposal, it did not. The Liberty, when it was shot up by Israeli fighters, was eavesdropping on the Six Day War of 1967. Thirty-four crew members were killed and 170 wounded.

Before the Pueblo sailed on her own eavesdropping mission against North Korea in 1968, Rear Adm. Frank L. Johnson, commander of naval forces in Japan, warned her skipper against looking provocative - against using the guns that he did not feel should have been put on the Pueblo.

"I was not in favor of arming AGERs, said Johnson later in reference to Navy electronic intelligence ships. The admiral considered the right of U.S. ships to sail in international waters the best armament.

"I was not particularly happy about the thought of my captains having armament of their own," Johnson told a naval court of inquiry that investigated the capture of the Pueblo off Wonsan, North Korea.

The officer given command of the Pueblo on her sensitive eavesdropping mission was the same Lloyd M. Bucher.

Cdr. Bucher, before he took the Pueblo from Japan on his mission, was personally warned against doing anything provocative. "Don't start a war out there," Bucher said one admiral told him.

When North Korean torpedo boats started harassing the Pueblo off Wonsan on Jan. 23, 1968, Bucher followed the script he had been given. He played a sea-going game of "chicken," refusing to obey orders of the North Korean skippers sighting their guns on his ships.

The Fubini theory of arming a ship only with the historic rights to international waters blew up as soon as the first North Korean shell ripped into the hull of the converted cargo ship Pueblo. Nothing was the same after.

Bucher told the court of inquiry that "I was completely and hopelessly outgunned" by the two North Korean torpedo boats, one on each side of the Pueblo's bow.

"I knew [that] to send a man up to that gun" on the Pueblo "would have meant certain death for him because he would have been walking within 30 yards of a mount of machine guns" on the torpedo boats. "I saw no point in senselessly sending people to their death," Bucher said.

Bucher surrendered his ship to the North Koreans. The admirals on the court of inquiry recommended him for court-martial. Navy Secretary John H. Chafee refused to let Bucher or his crew be court-martialed, declaring in 1969 that they had "suffered enough."

Richard M. Nixon, running for President in 1968, twitted President Johnson for failing to retaliate against North Korea for capturing the Pueblo.But when a Navy EC-121 electronics intelligence plane was shot down on April 15, 1969, by North Korea as it circled off that country's shores, killing all 31 crew members, Nixon - who had become president - did not order retaliation.

The lesson of the Pueblo - underscored by the shooting down of the EC-121 - was that small as well as large countries will risk war rather than tolerate highly eavesdroppin that they can stop.

In the 10 years since the Pueblo was captured, the United States has retired those intelligence ships: reduced reconnaissance by submarines, and turned increasingly to satellites, drone airplanes and ground intercept stations in friendly countries bordering on targets of interest for espionage.

The emphasis now is on spies that do not bleed or sign, under torture, embarrassing "confessions."