KING Hussein of Jordan ''surprised'' President Reagan by postponing for ''as long as things are as they are'' any idea of talks with Israel. His decision not only puts on ice a possible new beginning toward peace in the Middle East. It also suspends a package deal which included United States equipment for an 8,000-man Jordanian mobile strike force much desired by the Pentagon for help in protecting the oil of the Gulf. Jordan was to have been provided with Stinger (three-mile range) antiaircraft weapons in the same package.
King Hussein says he needs the weapons and intends to get them from anywhere he can (by implication even from the Soviets). He takes the position that under existing conditions the American price is ''too high.''
While in Washington the King talked with the President on Feb. 13 and 14. Apparently the White House thought all was well - until it read the New York Times of March 15 carrying the text of a Times interview with the King in which the King said that the US had lost its credibility as a mediator in the Middle East.
The question is, what happened between Feb. 13 and March 14 to cause the King to reject the American package.
For the answer we go back to that United Nations Resolution 242, which was framed at the conclusion of the 1967 war and has been the foundation of all peace efforts between Israel and the Arabs since. Resolution 242 called for Israel to withdraw from occupied territories in return for Arab recognition of, and peace with, Israel - a trade of Arab land back to Arabs for peace.
The US helped draft that resolution. It was adopted unanimously in the UN. Israel voted for it. The Camp David agreements were written within the framework of Resolution 242. President Reagan's September 1982 redefinition of the Camp David formula reaffirmed 242. On Feb. 13 President Reagan reassured the King of his, the President's, continued support for 242.
US diplomacy has interpreted Resolution 242 as meaning ultimate Israeli withdrawal from all the occupied territories subject to ''minor frontier adjustments.'' The Israeli government refrained from challenging that interpretation publicly until Menachem Begin became prime minister in 1977. Arabs continue to assume that it means ultimate Israeli withdrawal from the West Bank, the Gaza Strip, the Golan Heights, and east Jerusalem.
Israeli settlements were planted on occupied lands before Menachem Begin became prime minister, but privately, not officially. Some were dismantled by Israeli armed forces. The methodical, overt building of such settlements began with the Begin-Sharon-Shamir regime from 1977. Since then the building has been pushed officially, steadily, and extensively.
President Carter repeatedly called such settlements illegal. Camp David called for suspension of the building. The more such settlements, the less the likelihood that the lands will ultimately be returned to the Arabs. Between Feb. 13 and March 14 King Hussein wrote a letter to President Reagan asking him to support, or at least refrain from vetoing, a Jordanian resolution calling the settlements illegal. The US delegation at the UN vetoed a similar resolution last year. The President refused the King's request that this time the United States not veto the action.
The White House said it was surprised when it heard that the King had abandoned the package. It should not have been surprised.
If the US treats the settlements as being illegal (which it did from 1967 down to the Reagan administration), then Jordanian talks with Israel would deal with such details as when the Israeli withdrawal would begin and what kind of Arab government would be set up as the Israelis pulled back. But if the settlements are treated by the US as ''not illegal,'' then the US has abandoned 242 as the beginning point for negotiation.
To any Arab this is vital. The King tested the President's commitment to Resolution 242 by his request. From his point of view the President abandoned 242 by refusing to stand aside on the matter of settlement legality. It would be astonishing had King Hussein done differently.