The arrival in Miami of the deposed Nicaraguan tyrant, Anastasio Somoza Debayle, vividly recalls Mort Sahl's poignant, heart-rending account of a similar event years ago.

The humorist was describing the disembarkation in San Francisco of the late South Korean dictator, Syngman Rhee, who had to flee his country following a democratic uprising against him.

There the poor fellow was, Sahl sadly noted, staggering down the gangplank, bent over by the weight of two old battered suitcases, bulging with all that remained of his wordly possessions - $9.6 million.

That, of course, is chicken feed compared with what Somoza is reputed to have salvaged. The extimates run to $500 million or more, but the only thing known for sure is that, when the leaders of the Nicaraguan revolution took over, they found the country had been virtually stripped of everything of cash value. The banks, for instance, were merely hollow shells.

Nevertheless, Somoza is not without sympathizers in the United States (especially on Capitol Hill) who are wringing their hands over the despot's downfall, and complaining about our government once more "abandoning" old proteges like Somoza and the shah of Iran.

It is true that in recent years the United States had been "losing" a flock of anti-democratic clients who, through natural deaths, assassinations, revolutions and other "acts of God," have been removed from the scene.

The fortuitous result of all those changes has been to free the United States of reckless commitments and dangerous overextension of Yankee power around the globe. And so some Americans think that, beginning with Somoza, we ought to start counting our blessings.

In this hemisphere, we no longer are obliged to prop up dictators like Batista in Cuba, Papa Doc Duvalier in Haiti or Trujillo in the Dominican Republic. Nowadays, there isn't a U.S. Marine anywhere in the Caribbean or Central America protecting unpopular governments against the natives.

The CIA, of course, helped undermine elected governments in Guatemala and Chile, but the generals who dominate those countries now understand that in the light of the Nicaragua experience, they can't count on the United States to save their necks.

Our luckiest "losses" may have been in Asia, where the defeats of Gen. Nguyen Van Thieu in Vietnam, Lon Nol in Cambodia, and the late Generalissimo Chiang Kai-shek In China, have freed the United States of its mot costly commitments of the post-World War II era. There are those in Congress, however, who would like to recommit the United States to the defense of Chiang's son, who heads the Nationalists on Taiwan, but they are not likely to succeed.

Nevertheless, there remain some hangovers to worry about, chiefly our commitment to Park Chung Hee, the military dictator of South Korea, that could still involve us in another Asian mainland war, and to Ferdinand Marcos, the Philippines strongman.

Yet, their days, too, may be numbered, if the trend of recent years continues. Who would have thought, not long ago that democratic movements in Spain and Portugal would supplant such old U.S. collaborators as Franco and Salazar?

It must be argued, though, that all this, in the eyes of our cold warriors, looks like an American "retreat." To them, it is the abandonment of the socalled "American Century," the rejection of Pax Americana, the collapse of "national will," and the "loss of America's faith in itself."

But they are discouraged, for they realize the American people would vote a resounding "no" if again opportunity of intervening militarily in Vietnam, launching another Bay of Pigs invasion, sending the troops to be Dominican Republic or marching to the Yalu.

It is said that God looks after children, drunks and the U.S.A. It seems to be so, for the country appears to have learned the hard way that discriminating internationalism is a prudent and practical alternative either to compulsive interventionism or blind isolationism.

President Carter could hardly have stated it better when, at his latest press conference, he was asked what the United States was going to do about the alleged, but unfounded, communist domination of the Nicaraguan revolution. He said:

"It's a mistake for Americans to assume or to claim that every time an evolutionary change takes place in this hemisphere that somehow it's a result of secret, massive Cuban intervention. The fact in Nicaragua is that the Somoza regime lost the confidence of the people.

"To bring about an orderly transition there," he added, "our effort was to let the people of Nicaragua ultimately make the decision on who should be their leader - what form of government they should have." Amen.