Americans seem to have a curiously split view of their presidents and foreign policy.

At election time, domestic issues dominate and most foreign concerns hardly seem to matter. Yet once a president takes office, it's foreign problems that inevitably demand much of his time and become a key test of his leadership.A campaign that cut away the posturing and the extravagant statements on both sides might help clarify some policy choices that await the nation in the next decade.

We inhabit a world that is largely non-white and largely poor, where surging populations hinder economic growth. It's a world where competition and linked-up economies demand bold new strategies for continued U.S. prosperity; where new thinking is shaking up preconceptions in the communist world, and where Europe is evolving toward new political arrangements in perennial concerns over terrorism, the Middle East and the global environment, and it's clear that any incoming president will have plenty to do.

It's too late to squeeze the nonsense out of this campaign. But in looking ahead, it helps to realize that the next president, facing radical changes abroad, will have the job of redefining America's world role. He can't do this with pieties about armed strength (Bush) or banalities about making "tough choices" (Dukakis).

On the unsteady world economy, for openers, the next president can hardly avoid coming to grips with the burgeoning Third World debt and the costly U.S. trade imbalance.

He has serious rebuilding to do on relationships with Latin America, which have been cramped by the Reagan administration's futile preoccupation with arming the rebels in Nicaragua. A full-court press on Central American peace negotiations, redoubled efforts to stem the illicit flow of drugs, and a major effort to forge closer links with Mexico should be high on the agenda.

In the Middle East, continued tensions over the Israeli-occupied territories and skirmishes in Lebanon demand a more innovative U.S. role than the Reagan administration has chosen to play. Security in the P U.S. concern, even with the end of the Iran-Iraq war. And South Asia, with both Pakistan and India facing landmark elections, will become a more sensitive region than usual. Africa, much of it beset by crisis, warrants more U.S. attention.

Dealing intelligently with the Soviet upheavals will challenge the new president to be adaptive while being alert. While neither Gorbachev nor his perestroika is immortal, some changes at work in the Soviet Union will have lasting effect on how the USSR presents itself abroad. This prospect invites fresh thinking on a host of questions, from the structure of NATO to the possibility of cooperating on problems of protecting the environment and aiding development in poor countries. Arms control will demand a top priority, particularly in keeping up momentum toward a follow-up agreement to the INF treaty in Europe.

In any of these areas, shaping prudent U.S. policy for the 1990s demands realism, balance and vision. It demands the ability to attract top people, to think creatively and to make decisions unfettered by past failures. In the making of foreign policy, it demands openness, consistency and accountability.

These are the qualities, more than patriotic utterances or promises of more military hardware, that can mean an effective global role for America in the years ahead. These are the qualities that should have been explored in detail by the campaign now drawing to a close.