Whenever there is a change in the leadership of one of the superpowers there can be changes in policy - foreign as well as domestic. The difference between Soviet foreign policy from Leonid Brezhnev to Mikhail Gorbachev is massive. There has been some anxiety, particularly among friends and allies, about what may emerge from the United States' presidential election year. Most such anxiety can now safely be put aside. Voting on Tuesday in 20 states eliminated from the running those candidates who, at least in their rhetoric would, if they ever had the chance, make major foreign policy changes.
Neither Pat Robertson of Virginia nor Richard Gephardt of Missouri did very well in the voting. They are the only two of all the candidates who talked serious change in existing foreign policy.
Jesse Jackson did well in the Tuesday voting and would, if ever in the White House, cut back on defense spending and try to use persuasion rather than bullets on Daniel Ortega of Nicaragua. But there seems no prospect of his getting the nomination.
Robertson belongs to the early Reagan ``Russia-is-the-source-of-all-evil'' school. Gephardt has been preaching a drastic change in trade policy which, if ever implemented, would likely mean a trade war, particularly with Japan and West Germany, thereby putting a strain on the existing system of alliances and associations which tie the US to Western Europe, Japan, and China.
The US now has a consensus foreign policy. It has never been officially identified. It is, in fact, a policy which calls for seeking a tolerable level of coexistence with the Soviets while cherishing a military and political system of associations with Western Europe and Japan and China.
This has gradually emerged since Ronald Reagan came to office, preaching the overthrow of the Soviet regime by economic blockade. Early Reagan lieutenants used to mutter about being in ``a pre-war situation.'' Mr. Reagan's former secretary of defense, Caspar Weinberger, talked about a ``war-winning'' US capability, even in the nuclear age.
All of that has long since eroded away along with most of the people in the Reagan entourage who believed either in inevitable war with the Soviets or the possibility and desirability of bringing down the Soviet regime by economic warfare.
In early Reagan days, people who talked and thought that way were placed strategically all through the higher levels of policymaking. Jeanne Kirkpatrick at the United Nations, Richard Allen at the National Security Council, Caspar Weinberger and Richard Perle at Defense, and Gen. Alexander Haig at State were all of the ``confrontationist'' school of thought about East-West relations.
Haig wanted to isolate Castro in Cuba, and gave an orange light to the Israelis to invade Lebanon. Kirkpatrick and Weinberger tried to whip the alliance into a broad policy of economic blockade against the Soviets. Perle opposed any negotiations with the Soviets looking toward arms control.
Today there is one sole survivor at a high policymaking level from that old school of original Reagan warriors. He is Elliott Abrams who still runs the Central American section at the State Department and battles daily and devotedly for the Nicaraguan contras.
The others have all gone. George Shultz runs the State Department and is pursuing diligently a search for more and better arms agreements with the Soviets.
Mr. Reagan himself will be going to Moscow before the summer is out. His trip will be a symptom of an observable fact: The second ``cold war'' is over, and Mr. Reagan is presiding over a new condition which amounts to a dawning of a second ``d'etente'' in US-Soviet relations.
Republican Robertson was the only one of the candidates in either party who advocates any turning back from this course, which has evolved out of the various pressures on Mr. Reagan and is the existing bipartisan foreign policy of the US.
Democrat Gephardt was the only one who preached the kind of economic policy which would have put a dangerous strain on the system of alliances.
Robertson claims that he will stay in the race right down to the Republican convention. He can. He will have a small bloc of delegates at the convention. He might even be allowed a nomination speech and a small parade. Gephardt might as well bow out, as he probably will if he does just as poorly in Illinois next week.
The surviving and leading candidates are mainliners in foreign policy. None has said anything against either the system of alliances or the new ``d'etente.'' There is no reason to think that either Bush or Dole, the Republican survivors, or Dukakis, Gore, or Jackson, the Democratic survivors, would depart from a pro-alliance policy or from ``d'etente.'' In fact, foreign policy has had little attention in the campaign so far, with one exception.
All of the candidates, survivors and casualties alike, have talked about ``making America more competitive'' in the economic world. Perhaps it can be called a new urge toward ``economic nationalism.'' It is as yet vague and blurred. No one has defined it in detail. It is an urge to do something, anything, which might help to bring the foreign trade of the US back into balance.
But there is no reason yet to think that it might lead toward serious economic isolationism.