It is not easy to explain to foreign friends, or even to ourselves, what the Iran-contra hearings are about: all those lawmakers, all those lawyers, all that testimony, all that investigation. So far there have been arms sales, crazy cakes, Swiss bank accounts, a beautiful woman -- but not nearly enough spies or sex or corruption to explain the enormous expenditure of public money, time, newsprint and American reputation.

There has been talk of private profits and ''private government.'' But thus far all references to corruption have come down to an insurance policy, some snow tires and an alarm system. If after enormous investigation nothing more is found, then never will so many distinguished men have spent so much time and so many taxpayer dollars to uncover so little ''payola.''

I am not quite certain what ''privatizing'' foreign policy means. There are a good many American private citizens involved in Nicaragua, some on one side and some on the other, but Congress has evinced little serious interest in investigating that matter. There is also a longstanding practice by the U.S. government of subcontracting to private concerns certain kinds of covert activities. But so far no evidence of illegality in these activities seems to have emerged.

These hearings are not like the Watergate hearings. The Watergate hearings began with a crime -- a break-in -- and arrests that led more or less directly to a presidential campaign organization (remember CREEP?), to the CIA (remember Howard Hunt?), and to the White House (remember John Dean?).

The offense that triggered the Iran-contra investigation was not an illegal act like a break-in. Rather, it was a leak in a Middle Eastern newspaper concerning a U.S. effort to open a channel of communications with Iran, an effort that had been secret.

The question of executive-branch secrecy has thus been central from the start. Does the executive branch have the right to withhold any information from relevant committees of Congress? Did the president illegitimately withhold from Congress information about authorization of arms sales to Iran?

The same secrecy issue lies at the heart of the ''Elliott Abrams question.'' Abrams has admitted that he misled Congress with regard to securing financial assistance for the contras from the sultan of Brunei. Secretary of State George Shultz has written a letter in which he reiterated the explanation Abrams had already offered concerning this event.

''At the time Mr. Abrams gave his testimony, we had given that country a pledge of absolute confidentiality and Mr. Abrams felt bound by that pledge,'' Shultz said.

Abrams has since characterized his misleading testimony as ''a great mistake'' and has apologized to Congress.

It seems clear that Abrams should have found some other way to deal with his conflicting obligations. But it also seems clear that Congress should have found some other way to deal with its conflicting obligations, and to honor U.S. commitments of confidentiality to Brunei, Saudi Arabia and others.

Like Congress, Abrams is committed to upholding the law, and also to taking care to protect the United States against enemies foreign and domestic. Some members of Congress are speaking and acting as if they believe Ronald Reagan and his administration are the enemy against which the United States is to be protected.

The investigating committee takes a more moderate view. However, it uses its investigative powers to lay bare aspects of foreign policy against which less judicious opponents then move. The committee thus becomes part of this contest over control of U.S. foreign policy.

Abrams has become a symbol of Reagan's policy of support for the contras. Therefore, the strongest opponents of that policy think Abrams should be fired for having implemented it with energy, skill, dedication and considerable success.

Rep. Edward Feighan (D-Ohio) is one of what are nowadays called liberals who recently have written the secretary of state requesting that Abrams be fired. Feighan and his friends would like to impose on Reagan an assistant secretary for Latin American affairs who would implement their policy for Nicaragua -- even if they could not find the votes to enact it.

All they have to do is intimidate the Reagan administration. George Shultz, to his credit, has declined to be intimidated.

No wonder foreigners do not understand what is going on today in American government. No government works quite like this one. Nor did the Founding Fathers foresee that ambition would counteract ambition quite this way.

Maybe we ought to have some congressional hearings on the problems of divided government.