This country is up to its foreign policy in kangaroos.

There may be as many as 40 million of them, and that is a matter of no small concern to the scant 14 million Australians.

The United States -- perhaps you'd better sit down for this one, Yanks -- is a major cause of the problem. It is hoped you will be part of the solution.

Nothing -- not the Pentagon's dreams of a Navy base on our southwestern coast or U. S. dominance in our mining industry -- has touched Australians' emotional quick like the U.S. attitude toward the shy, bounding marsupial.

By and large Australians have an affectionate regard for the kangaroo, that curious eddy in the evolutionary stream. He's on our coat of arms and there's a move afoot to put him on the national flag. Nevertheless, there are limits. After all . . . 40 million of them . . . leaping around the outback, competing for water and range grasses against the cattle herds.

To be perfectly fair, the great kangaroo explosion was started by Australians. When Gough Whitlam and the Labor Party swept to victory in 1972, it came into favor on a wave of nationalism-cum-conservation.

The Labor Party became both the womb and the focus of groups that wanted the kangaroo to become Australia's national symbol and were fearful it was near extinction.

Whether the fears were justified or not will probably never be known. Australia is such a vast country -- just a few square miles smaller than the continental United States -- that nobody has ever seriously claimed to have counted the kangaroo population.

What was known six and seven years ago was that a significant industry had developed based on the export of kangaroo products, particularly the hide, which tans to a luxurious leather. Wildlife conservationists, who were staunch supporters of Whitlam's election demanded a ban on the export of kangaroo products, even though a serious analysis of the kangaroo population had never been done.

In 1973, an export ban of sorts was imposed but was never completely effective, partly because of strong opposition from some Australian states.

In 1975, with the advent of the Conservative government of Prime Minister Malcolm Fraser, the ban was lifted entirely.

In the interim, concern for kangaroo had made its way to the United States. In January 1975, the administration of then president Gerald Ford slapped a ban on the import of kangaroo products.

The U.S. move unsettled many Australians, influenced partly by what some regarded as foreign interference in a domestic issue, but primarily by an explosion in the kangaroo population that was well underway. Public opinion here swang over in favor of a reasonable culling of kangaroo herds.

Over the past two years, almost every Australian Cabinet minister of any consequence has campaigned in Washington to have the import ban lifted.Prime Minister Fraser has raised the question during each of his five visits. Meeanwhile, the herds continue to multiply.

The issue brings us to one of those crucial times of testing for a long-standing alliance. Our countries were side by side in both world wars. We joined you in Korea and in Vietnam. You're taking our ores.

Would you think the less of us if we sometimes think fondly of those eager young Americans streaming annually from your graduate business schools. Each one of them is automatically a customer for an attache case, made -- and let us be perfectly frank as only old friends can be -- of fine kangaroo hide.