The situation gripping British national attention seems unprecedented. Five-week-old Siamese twins Jodie and Mary share but one heart. Doctors believe both will die if not separated soon; Jodie, the stronger twin, would get the heart, and Mary would perish, deliberately killed by the surgery. A British court has ordered that the operation proceed. The parents, devout Catholics, oppose any surgery because they cannot bear the idea of Mary being killed.

According to British news reports, the Rev. Cormac Murphy-O'Connor, the archbishop of Westminster and England's highest-ranking Catholic, has advised the courts that it would be better to do nothing at all, letting both girls die, than to kill one in order to save the other. Yesterday, Lord Justice Ward, who is reviewing the legal appeal, declared that he is "on the horns of an irreconcilable dilemma" and can find no similar case to guide him.

In fact, an almost identical case occurred in the United States in 1977 and was just as morally wrenching but decisively resolved by the chief surgeon--C. Everett Koop, later to be surgeon general and renowned as an extremely dedicated pro-life proponent. In that case Koop, pro-life in every way, killed one twin to save the other.

Here was the background. First, it is important to know that long before Koop became politically prominent--initially as an opponent of abortion, later as an opponent of cigarette smoking and proponent of AIDS action--he was celebrated within the medical community as the founder of modern pediatric surgery.

Beginning his work at Children's Hospital of Philadelphia in the late 1940s, Koop made pediatric surgery much safer and more effective by pioneering surgical and anesthetic techniques meant for small bodies and metabolisms, and by championing pediatric surgery as a subspecialty. He developed many basic children's operations still used today, and as a research clinician, established the existence of and therapies for childhood cancer. Until Koop, the medical community believed that only adults could contract cancer, with the result that many children died of undiagnosed cancer. Koop also saved numerous infants born with extreme birth defects, ones other doctors had given up on and whom utilitarians might claim would be "better off" expiring. Not one of them, Koop later said with justified pride, ever returned to him as an adult and complained about being saved.

And Koop learned how to separate Siamese twins, once thought impossible. In 1957, Koop became an international sensation when he separated two female twins. One died nine years later of heart failure, but the second thrived, and Koop has said that his most prized possession in life is a picture of himself with the twin on her wedding day.

In 1974, Koop became a medical star again when he performed the Rodriguez separation. Clara and Alta Rodriguez were Siamese twins of a type called "ischiopagus tetrapus," sharing a liver, colon, and parts of the intestines, with their entire trunks merged. What they were barely looked human, and the case was considered hopeless. Directing a team of 23 surgeons, technicians, and nurses using equipment he specially designed for the Rodriquez girls, Koop separated the twins. Two years later, Alta died in a choking accident, but Clara grew into a healthy adult. "Even the other surgeons were in awe of Koop on that day," one of the doctors present told me for my 1991 book "Surgeon Koop." "It was as if he had worked a miracle, in the true sense of doing something beyond physical law."

No miracle was possible for the Siamese twins brought to Koop's hospital in 1977, however. Like Jodie and Mary today, these twins (whose names were never released, in keeping with their parents' wishes) shared a single heart. If separated, one would die. If nothing were done, in a few months or at most a few years, both would die because a single heart cannot pump for two grown bodies--the same demise Jodie and Mary face if nothing is done.

In the 1977 case, the parents were Orthodox Jewish. Shortly after they arrived with their twins at Children's of Philadelphia, a small army of Orthodox rabbis and Talmudic scholars pitched camp in a wing of the hospital, trying to decide the correct course. The rabbis, and the parents, eventually came to the lesser-of-two-evils position: One death would be less horrible than two deaths. The rabbis interviewed all the members of the surgical team, looking for information and spiritual insights on subjects as arcane as exactly how the babies would be touched in the moment when one of the lives were lost.

Unlike the current British case, there was no lawsuit in the 1977 Philadelphia decision. The questions were, first, what did the parents want? The parents wanted surgery to save at least one. The next question was, what did the rabbis think? After extended debate, the rabbis felt that God would approve. The final question was, would Koop do the operation?