THE CAREER soldiers are still there, and the doctors and the technicians. But they no longer operate with what used to be called military efficiency. And they no longer bully the Arlo Guthries of the world.

The austere fortress on Whitehall Street, for years an American Bastille in the eyes of activists, has fallen to the times.

Twenty of us from New Rochelle arrived there one recent morning, courtesy of Local Board Number Nine, to see and be seen and, perhaps, reclassified. Our group was an ethnic reflection of our city: Italians and Irish from the South End, by the Sound, Blacks out of the battered center city, and Jews, clutching medical reports and X-rays, from the North End.

"What have you got?" asked Larry Stillman of John Margolis, en route to the induction center.

"Two allergists' reports and notes from a doctor and a shrink. How about you?"

"I just have a note from a shrink."

"That's enough. I just wanted to make sure, myself."

An hour later, at the center, John Larga, who was down at Whitehall for his third physical, asked an officer how long a drafted man has to serve. "Two years," replied the officer. Larga looked surprised. "Good," he said, "I thought it was three or four years."

John Larga had not thought to bring a note.

The processing of potential draftees is a lengthy and confused business. The induction center has eight floors, bridged by rickety stairs and an ancient, attendant-operated elevator. Registrants are required to proceed from room to room and floor to floor in seemingly random order.

The men who direct the nervous human flow-soldiers and doctors-are almost uniformly young. Many of them, perhaps half, are black. They function like workers on an assembly line at an automobile plant; without enthusiasm, without complaint.

Sergeant Petti, a small man who was trying hard to grow a moustache, administered the intelligence test to most of the New Rochelle group. "This is a four-part test," he said in a monotone, reciting from memory words that the rest of us followed in our test books. "There are arithmetic questions, questions dealing with verbal skills, visual questions, and puzzle questions."

When he finished reciting the instructions he warned us not to try to flunk the test because they had ways of finding out and, anyway, the results would go in our permanent records and we might not be able to get jobs.

"Are you threatening us?" someone asked.

Sergeant Petti looked at him and said in a tired voice, "I'm not threatening anyone. I've got 101 days left and I'm just trying to do my job."

THEY were all just trying to do their jobs; the woman at the hearing test, the guys who took urine samples and blood samples and X-rays and measured height and weight, they were all courteous.

Some of them even sympathized with the confused, anxious men, who wandered the dimly-lit halls in various stages of undress. A doctor, noting that one registrant had filled in as occupation, "Human Being," said to him, "This business isn't dehumanizing just for you. It is for all of us."

During a full day at Whitehall I saw only one soldier, a major who had been there since 1966, who evinced any enthusiasm for what he was doing. He looked like a soldier on leave in a June Allyson Korean War movie-crew cut, perfectly pressed uniform, shiny black shoes, braid on his shoulders and ribbons on his chest. He said things like "Chow will be at 1:00 sharp, men," and "When you receive your orders, proceed to your assignment, on the double." He was an anachronism, even there.

Most of the soldiers at the center had been there less than a year, long since the war and the military had come under serious attack. They certainly had no pride in their jobs and, one sensed, they might have been embarrassed by them.

The officer in room 204, the one who makes all final decisions about who does or does not pass the physical, had drawn peace symbols on his loose-leaf notebook. He spoke to each registrant softly and sympathetically and, in the end, rejected a startling number.

John Larga failed, again, because of something in his urine. A Czech, who had been in the country for two years and hoped to become a citizen, was rejected because he didn't speak the language well enough. Larry Stillman got his psychiatric deferment. A guy named Louie, a hustler of drugs and women, was judged immoral for the Army. Someone else got out on high blood pressure by squeezing the side of the chair with his free hand during the test.

In all, only five of the New Rochelle contingent passed the physical. And there was solace, even for them. As one of the unfortunates was told, by a luckier registrant wielding an X-ray like a bloody sword, "All you have to do is ask for a personal appearance in New Rochelle. The examiner there is a Dove and he'll put braces on you himself before he'll accept you."