June 13, 1985

''When asked what I thought should be done if the people were guilty, I said I thought they should be shot, though I supposed hanging is the preferred method.'' - Defense Secretary Caspar W. Weinberger, discussing those who spy in peacetime. [B8:5.]

As the train from China crosses the Yalu River, there is no mistaking the legacy of war. A hundred yards downstream stands a second bridge, with all six supports on the North Korean side of the river missing, blown away by American bombing. Nearly 32 years after the armistice that ended the Korean War, the first thing a traveler sees on arrival in this tightly sealed nation is a reminder of the destruction wrought by American forces under Gen. Douglas A. MacArthur. In October 1950 United States troops approached within a few miles of the Yalu, prompting the Chinese to enter the war. The evidence is even starker where the express from Peking halts, beside a red-and-white barrier manned by a soldier in the olive green uniform of North Korea's army. Between the shoreline and the first of the concrete bridge pontoons is a tangled mass of rusted steel. On shore, workmen are busy clearing it away for scrap.

Defense Secretary Caspar W. Weinberger said today that a way should be found to execute people who passed military secrets to hostile powers in peacetime. He said that John A. Walker Jr. and three associates, facing trial on charges of spying for the Soviet Union, ''should be shot'' if convicted. Mr. Weinberger said that a committee had been formed to determine whether the Uniform Code of Military Justice should be changed to allow execution of military personnel in peacetime. Under present military law, conviction in a military court on espionage charges carries a mandatory death sentence only in wartime.

A music listing in The Guide Sunday gave an incorrect date for the singer Tim Strong's engagement at the Silver Lining, 349 West 46th Street. He will perform Friday.

Four members of a Harlem gang that deals in heroin and routinely kills competitors have been arrested on murder, drug and conspiracy charges, the Manhattan District Attorney said yesterday. The gang members were seized Tuesday night, three of them as they left to carry out a contract murder on upper Broadway, according to the District Attorney, Robert M. Morgenthau. The arrests culminated a 19-month investigation by the District Attorney's office in cooperation with the 28th Precinct detectives and the Police Department's Narcotics Division.