Try and strangle me, please," 66-year-old Imi Lichtenfeld of Tel Aviv politely asks one of his students. As the neophyte lunges, Imi's rigid palm shoots out and quivers at the attacker's windpipe. "I didn't want to fight," explains Imi. "Now you don't want to fight. In fact, you're lucky if you're still alive."

Imi, 5'6" and 150 pounds, is the creator of a deadly martial art called krav-maga. The name comes from the Hebrew words krav for fight and maga for contact. The irreverent call it "Kosher Kungfu."

It has become internationally recognized, with eight black-belt holders. But in its pure form, krav-maga is too dangerous for widespread competition. "When a martial art becomes a sport, like judo for example, the lethal movements have to be restricted," says Imi. "This destroys the basic principle of krav-maga: You automatically end the fight by putting an end to your opponent."

Imi teaches at a gym outside Tel Aviv. Childless, he lives nearby with his wife of 16 years, Elana. When the Israeli army was formed in 1948, he was the regimental sergeant-major in charge of all hand-to-hand combat training. "What I was teaching," he says, "was a unique combination of judo, karate, akido, kungfu and boxing." His tactics are now standard in the Israeli forces. If the Israeli paratroopers on the recent Entebbe rescue mission had fought the Ugandans hand to hand, they would have used krav-maga.

Imi programs his students as though they were computers. "Once you have all the tapes inside your head," he promises, "you can beat anybody. Your eyes are figuring the angle your body is forming with an opponent and making calculations for you."

The essence of krav-maga is economy of motion coupled with imaginative embellishments on the other martial arts, which Imi thinks are too inflexible. Imi's pupils are taught to limit opponents' blows to the outsides of their arms and legs while striking at the throat, belly, chest and groin. "I've developed one knife move," says Imi, "that no opponent can stop. But I don't want to put it down in print. It's too dangerous."

Imi was raised in Bratislava, Czechoslovakia, where his father, Samuel, was a police inspector and a European pioneer in the martial arts. "He founded a jujitsu school in 1907," Imi remembers. "He was a good policeman. He had to be tough to survive."

So did Imi. "I began fighting anti-Semitism in the '30s," he says. "When the Hitler youth gangs used to single out Jewish young men on the streets, it was either hit or run. I found the hitting more satisfying."

During World War II Imi served with a Czech exile regiment, which he joined after being rescued from a sinking ship in the Mediterranean by a British destroyer. Most of his family died in the Nazi gas chambers. At war's end he settled in Palestine. A civilian since 1963, Imi still puts in a full day, specializing in instruction to paratroopers, commandos and phys ed teachers.

Currently Imi is trying to modify krav-maga so that nonlethal self-defense can be taught to Israeli youngsters. "I want everybody in this country," he says, "to be ready for a fight."