"No employee of or individual acting on behalf of the United States government shall recognize or negotiate with the Palestine Liberation Organization or representatives thereof, so long as the Palestine Liberation Organization does not recognize Israel's right to exist, does not accept Security Council Resolutions 242 and 338, and does not renounce the use of terrorism."

If that heavy language rings a bell, you may be thinking of Henry Kissinger's written commitment to Israel in 1975, restricting U.S. diplomatic access to the PLO as part payment for Israel's agreement to partial disengagement of its forces from the Sinai. If so, you probably believe that the Kissinger policy is not binding on further administrations. Just recently, Ronald Reagan and Jimmy Carter have both talked about it in a way that gives precisely that impression, that suggests the president has a free hand.

Not so. The language cited is the law of the land. Last October, it was surreptitiously tacked on to what is known as a "continuing resolution" -- the legislative last resort for funding government spending at current levels when Congress is unable to agree on new appropriations for the coming fiscal year. It's a lousy way to legislate anything, but that's only one reason why I bring it up.

Another is that it will come as news even to those who follow Middle East events with care. It was news to me until I found mention of it in a handout from the American Israel Public Affairs Committee, the Israel lobby, which had to know about it, having had a large hand in its enactment. It turned out, after asking around among knowledgeable authorities, to be news to almost all but a handful of administration officials, its congressional sponsors and the members of congressional committees who wrote it into the money measure without hearings. That was the only time the question was put directly to a vote.

If that's a poor way to legislate, it's an even worse way to make foreign policy -- as you would suppose the Reagan administration would be the first to agree. Only a few days ago, Secretary Shultz was lecturing his State Department employees on the terrible legacy of "congressional restrictions on presidential flexibility, now imbedded in our legislation" as a consequence of Vietnam and Watergate. "Not only the War Powers Resolution, but a host of constraints on foreign aid, arms exports, intelligence activities and other aspects of policy," the secretary said, have "weakened the ability of the president to act and to conduct foreign policy and weakened our country."

Yet Section 535 of last year's continuing resolution is specifically designed to restrict "presidential flexibility." It was actually inspired by revelations of secret meetings in 1981-82 between PLO representatives and a State Department consultant. Had it been in effect at that time, it would probably have prohibited the Reagan administration's successful mediation in 1981 of an 11-month cease-fire agreement between the PLO and Israel. It would have made it unlawful in 1982 for a U.S. envoy to deal even indirectly with the PLO on the arrangements for the removal of PLO guerrillas from Beirut under escort by a multinational force, including U.S. Marines.

Its terms, moreover, go beyond both the original Kissinger commitment and President Reagan's stated conditions for dealing with the PLO by adding the requirement that the PLO "renounce the use of terrorism."

The administration's acceptance of this tightened congressional restraint (while denouncing all other congressional meddling in foreign policy in general, and in Nicaragua in particular) speaks volumes about the spirit with which the Reagan administration approaches the responsibilities of what Shultz calls "global leadership" -- when the case at hand is the Middle East. The maintenance of "momentum toward peace in the Middle East" is Shultz's stated goal. You would assume it is also some part of his purpose for stopping by Jordan on his way back from a trip to Israel at the end of this week.

But the sense, shared among Arab and Israeli diplomats alike, is that the secretary is going through the motions and that the add-on of Jordan is a courtesy. That impression was reinforced by the downbeat reports on the recent swing through the area by Assistant Secretary Richard Murphy. The Israelis, it seems, are standing pat; Jordan's Hussein thinks he has gone as far as he can go. The core issue of Palestinian representation at any peace talks, in short, is unlikely to be resolved by Arab or Israeli initiatives.

That's not to say that the United States ought to make the procedural breakthrough by embracing the PLO unconditionally as a negotiating partner. But neither is it to say that the Reagan administration should abjectly abandon the right to play an energetic, questing, honest broker's role. Yet that's what's happening. When the instigators of section 535 in last year's continuing resolution tell you they have State Department encouragement for writing the same language (with provision for emergencies) into some more permanent piece of legislation this year, you have to figure that in the Middle East the high principle of presidential policy-making does not apply.