Mideast policies blur in N.Y. race.

New York should have been the state to clarify the Democratic candidates' views on the Mideast, but it wasn't. It should have been the place for wide-ranging discussion, not only because more than a quarter of its primary election voters are Jewish but also because bankers, oil consultants, and other Middle East-watchers can be found in New York. But this didn't happen.

Instead, Walter Mondale and Gary Hart got hung up on what many observers consider to be a nonissue at this stage - the proposal to move the United States Embassy from Tel Aviv to Jerusalem.

It is a nonissue, for one thing, some Middle East experts say, because once he became president, either Mr. Hart or Mr. Mondale might find it difficult to move the embassy. It is also a nonissue in the real world, as weightier matters would quickly crop up.

As former Undersecretary of State Joseph Sisco has pointed out, the proposed embassy move would not improve Israel's security. But its security could be affected by other issues, ranging from economic and military aid to arms sales, the Palestinian issue, and the Iran-Iraq war.

In the real world, the Iran-Iraq war could swiftly eclipse other issues, especially if Iran threatened oil lanes and nations on the southern side of the Gulf.

But the Democratic presidential candidates have touched only superficially on the matter of keeping the oil lifeline to Europe and Japan open. Mondale says that he would do everything necessary. Hart would support the Europeans, presumably with air and naval power, but would stop short of sending American ground forces.

Hart's posture appears to be in line with his reluctance to use force anywhere in the third world. But the question of oil from the Gulf - and militant Islam - deserves more debate. There is a Hart-Mondale difference here worth exploring.

When it comes to the much-debated Jerusalem embassy issue, meanwhile, Mondale charges that Hart was slow to endorse the embassy move and took the position that the issue should be decided by negotiations. Hart denies saying the location of the embassy should depend on negotiations.

Hart asks Mondale why the Carter administration failed to move the embassy. Mondale replies that Mr. Carter opposed such a move.

But there is little apparent difference between the two Democratic front-runners in their support for Israel. Their real difference is with the Rev. Jesse Jackson.

Mr. Jackson charges that the focus on Jerusalem amounts to a ''patronizing'' and ''pandering'' approach to Jewish voters. His view coincides with that of Hyman H. Bookbinder, Washington representative of the American Jewish Committee, who, in a New York Times column argued that Jewish voters do not constitute a monolithic bloc and will vote for the candidate who is most likely to deal effectively with a whole spectrum of issues.

''The Jerusalem issue is fraudulent,'' said one Jewish leader in New York, but he added that few Jewish leaders would be willing to go on the record with such a harsh comment. He himself asked not to be identified.

Jackson, meanwhile, has been proposing an independent Palestinian state and talks with the Palestine Liberation Organization, all within the context of security for Israel. But with Hart and Mondale diverted to the Jerusalem issue, their differences with Jackson have never been thoroughly debated.

In the end, if it's Hart or Mondale against Reagan, the Middle East may not be much of an issue. Reagan seems to have been virtually unscathed by the Lebanon setback. In his firm opposition to the proposed embassy move, Reagan looks almost statesmanlike.

The Democrats cannot accuse Mr. Reagan of failing to support Israel. He has increased grant aid, fashioned a new strategic cooperation agreement with the Jewish state, and canceled arms sales to Jordan.

But the Reagan experience also shows that any president is likely to modify Middle East promises once in office. As a candidate, Reagan called for an end to arms sales to Arab states and then ended up backing F-15 fighter and AWACS radar-plane sales to Saudi Arabia.

Candidate Reagan, in March 1980 assured Jewish leaders in New York that ''an undivided city of Jerusalem means sovereignty for Israel over that city.'' But within months, Reagan's advisers had inserted a much more cautious platform statement, saying that Jerusalem ''should remain undivided with continued free, open, and unimpeded access to all religions. . . .''