WASHINGTON— Thirty-two miles off the coast of China, the crewmen of the Navy reconnaissance plane spotted Chinese fighters closing in and knew they were in trouble. As the pilot struggled with his controls, radio operators began sending coded messages back to base reporting a possible confrontation. Partway through the second message, the transmission stopped. Minutes later the aircraft crashed into the East China Sea, killing all 16 crewmen. The date was Aug. 23, 1956.

''We seem to be conducting something that we cannot control very well,'' President Dwight D. Eisenhower told Admiral Arthur M. Radford, then chairman of the Joint Chiefs of Staff, in a secret meeting. ''If planes were flying 20 to 50 miles from our shores,'' Eisenhower continued, ''we would be very likely to shoot them down if they came in closer, whether through error or not.''

The history of the cold war is replete with international incidents involving electronic spying off dangerous coasts. Many had deadly outcomes. As the Bush administration struggles to resolve the standoff with China over the American spy plane and its crew now being held on Hainan island, it is time to consider whether this spying practice is still useful or if, with the end of the cold war, the risks now outweigh any advantage.

For at least half a century, American aircraft have quietly flown eavesdropping missions along China's coast. During the electronic spy wars of the early years of the cold war, scores of aircraft and hundreds of Americans were lost, mainly off Russia. Today, deep within Operations Building 2B of the ultrasecret National Security Agency, which is charged with these missions, stands a wall of black granite carved with the words ''They Served in Silence.'' Below are the names of 152 military and civilian cryptologists and analysts, most of whom died while on eavesdropping missions -- aboard planes and ships -- similar to that of the EP-3 now sitting on Hainan island.

During the early years of the cold war, the United States sent espionage missions deep into the airspace of China, using C.I.A.-trained Taiwanese pilots, and to Russia and North Korea. Unable to shoot down all the planes that flew over their territory, the countries resorted to shooting at them wherever they could find them -- often over international waters.

At times, the spy war came close to provoking military conflict. In the spring of 1956, the United States launched an extremely dangerous espionage operation. President Eisenhower authorized American planes with eavesdropping gear and cameras to cross into Russian territory. Six reconnaissance bombers, flying abreast, crossed the North Pole and penetrated deep into Russian airspace in broad daylight. The route chosen was a possible one for American bombing runs in case of a nuclear strike by Russia. If Soviet radar operators had seen the bombers, they would have had no way of knowing that the purpose of the mission was espionage, not war. But the United States was guessing that the Soviets did not have radar in that area, and on this occasion the guess was correct.

American ships on spy missions have also been lost. In 1967 Israel attacked the spy ship Liberty in international waters, killing 34 sailors and wounding 171 others. Fighters were launched from an American carrier in response. When Israel notified the United States that it had attacked in error, the planes were called back.

A year later, North Korea captured another American spy ship, the Pueblo, in international waters, killing one crew member and holding the rest hostage for a year. President Lyndon Johnson considered going to war with North Korea over the incident. The following year the North Koreans shot down a Navy EC-121 eavesdropping plane, again in international waters, killing all 31 aboard. Immediately afterward American aircraft in South Korea were placed on nuclear alert.

A great deal has changed since President Eisenhower, having just lost 16 men, questioned the wisdom of offshore air reconnaissance flights in 1956. The United States now has intelligence satellites that can eavesdrop on conversations almost anywhere in the world. They can also automatically create electronic ''orders of battle,'' lists of the locations and technical details of foreign radar systems. And land-based listening posts in Japan, South Korea and elsewhere are equipped with giant antenna farms focused on Chinese military, naval and diplomatic communications.

There are good reasons to consider ending our frequent, provocative, costly and often redundant close-in air patrols. The purpose of intelligence is to reduce tensions and the possibilities of war, not raise them.

Photo/Drawing (Brian Rea)