The ambassador of Lesotho was emphatic when she said, "The best American outreach to the poor nations of the world is still the Peace Corps."

'M'alineo N. Tau, envoy from a tiny and poor nation, an enclave inside South Africa, was telling me how helpful it is to have 80 American volunteers involved in the educational and agricultural development of her country. She said she had gone to Loret M. Ruppe, new director of the Peace Corps, to say: "We know America has economic problems, but it is our endless plea and earnest request that you do not cut down on the number of volunteers in my country."

I offer the good news that there are still 16,000 Americans who volunteer for Peace Corps service every year, and that 5,400 Peace Corps volunteers are in 60 countries this very day, living the way their impoverished hosts do, taking in an average of $297 a month, saying with their sweat, their skills, their caring that America wants Asian children to eat decently, African children to learn, Latin children to know a higher level of life.

Let me not overstate this case. The Peace Corps is not nearly what it used to be. The glamour is mostly gone -- faded from that August day in 1961 when the first 51 volunteers arrived in Ghana singing that country's national anthem in Twi, its national tongue. Having 5,400 volunteers in 60 countries now is a shameful comedown from the days in 1966 when we had 15,566 volunteers in 56 countries. There were 45,653 Peace Corps applicants in 1964, as against 16,195 in 1980.

Still, it is a testimonial to the depth of spirit and the doggedness of American volunteers that, after the publicity died down and the glory seemingly was gone, so many Americans, 18 to 80, would want to keep saying that America has a heart.

I can understand 45,000 people volunteering to live for two years in a village in Sri Lanka, Tanzania or Honduras in an era when the Peace Corps was being lionized on film, radio and television and in magazines and newspapers in most of the United States and the world; it is hard for me to understand why, when the Peace Corps has long been passe in the media, so many people are willing to give up precious chunks of their lives to be Good Samaritans in countries where the infant mortality rate could be 50 percent and the per capita income is a piddling $160 a year.

Peace Corps Director Ruppe told me that Americans still volunteer because they know that "economic conditions, due to inflation, due to the energy crisis, due to growing population and shrinking food supplies, are putting world peace and survival on the line" -- and thus the volunteers of the '80s know that a Peace Corps is needed much more now than it was that October day in 1960 when, at the University of Michigan, John F. Kennedy proposed "an international youth service program."

For 20 years, from Kennedy to Nixon, from Johnson to Reagan, the Peace Corps has enhanced this nation's security, simply because what these volunteers give is above politics and ideology. Still, like our Army and Navy, a Peace Corps contributes only according to the resources made available to it; and for more than a decade, the Peace Corps has gotten short shrift from the budget-makers. In constant 1972 dollars, the Peace Corps in 1966 got $148.6 million: last year it got $58.5 million. The budgeteers have almost let inflation kill the Peace Corps.

Somehow, in 20 years, the kingpins of the Office of Management and Budget and the appropriations committees in Congress have lost some sense of human values and priorities. They have virtually abandoned the most decent and compelling representatives America has, choosing to rely on things like MX missiles.