Does he have any fears?

''I worry about all the entertaining I'll have to do, about security, about the boredom of working the visa line,'' Aloisi confessed. ''But none of that is anywhere near enough to deter me.''

Randall Biggers, 30, of Roswell, N.M., now serving in Belize City, Belize, said that he had always been fascinated by anything distant. After attending the University of New Mexico, he served in the Peace Corps in Afghanistan, and that experience led him to the Foreign Service. ''I want to make some kind of impact with my life, on a big or small scale. I guess some of us are looking forward to living in Vienna or Paris. But I'd be just as happy to spend my days in the third world as a consular officer if I could help more people that way.''

Judith Cefkin, a 30-year-old Coloradan now at the American Embassy in Mexico City, said that years of living abroad with her parents and as a student had whetted her appetite for travel, new faces, new challenges. After graduating from Smith College, she tried journalism but found that she wanted to shed some of her detachment and become more deeply involved with the major issues of the day. ''I was just pulled toward the Foreign Service,'' she said. Asked if she had any apprehensions, Miss Cefkin said, ''I wonder what I'll do when I have to speak up for American policies that I don't agree with.''

Until a few years ago, the orientation course given to new diplomats consisted primarily of lectures on the foreign service, its traditions, discipline and ethics, how it was organized, how it works, how to do this job or that. The current curriculum covers the same material but does so through simulated situations and crises, such as trying to negotiate freedom for an American tourist jailed in the unfriendly land of ''Z.''

The initial six-and-a-half- week training is followed by five and a half weeks of consular training. Because consular work, despite its routine, is a major element in the day-to-day operations of any embassy, every new officer, whatever his or her cone, spends at least the first six months of diplomatic life as a consul.

Before they can gain tenure, a relatively new quality- control device, Foreign Service officers must become proficient in at least one foreign language. That training, which takes place either in the field or in Washington, can take up to five and a half months. It, too, relies to a certain extent on role playing and a simulated environment. ''You learn the words and usage that you will run into in your line of work,'' says Stephen Low, the institute's director and a former ambassador. ''We skip the detailed grammar. A lot of the time, we teach as though you were at your post abroad, talking to a businessman or politician. We're setting the standard in the U.S. for this kind of instruction.''

The diplomats in training also attend seminars at centers in nearby Virginia and West Virginia where for two and a half days they simulate every aspect of an embassy's operation. Their instructors, all veteran Foreign Service officers, alternately praise and goad, pushing and stretching to get the maximum performance. ''The tougher and more realistic the training is back here in the States, the fewer surprises the new guys are going to run into overseas,'' says James H. Morton, who runs some of the seminars.