The market -- that all-purpose barometer of the Reagan era -- has passed its judgment on the Reagan administration's Persian Gulf frolic. Whether you define the goal high-mindedly as protecting freedom of navigation, or more cynically as keeping a lid on Iranian and Soviet ambitions in the region, the larger goal is the same. It is to protect Western access to Middle East oil. That's the only reason we give two hoots about the Gulf.

Three months ago, after seven years of war between Iran and Iraq, the price of oil was about $18 a barrel, and the question was whether even that level could be sustained. Since the United States got involved, panic about future supplies has driven the price up to about $21 a barrel.

Thus the administration has accidentally achieved its all-but-official -- and all-but-insane -- goal of pushing the price of oil back above $20, from $10 last year, to benefit domestic oil producers. OPEC was willing to settle for $18. The other government most eager for higher oil prices has been Iran's. An extra $3 a barrel means about $7 million a day to finance the war effort. The price rise also means a welcome infusion of hard currency for the world's leading oil producer, the Soviet Union. Congratulations all around.

This was hardly the idea, of course. The idea was to show the world that the United States can behave like a superpower. The difference between a modern superpower and an old-fashioned imperial power seems to be that imperial powers used to exact tribute from their vassal states. Now our "allies" (the modern term) exact tribute from us.

As has been widely and grumpily noted, we get precious little oil from the Persian Gulf. Europe gets a lot and Japan gets a whole lot. To protect that oil, Japan is doing nothing, Europe is doing a bit, and we're doing a lot. It's true, as superpower-trippers respond, that a cutoff of Mideast supplies would drive prices up for all importers regardless of their source. But the United States is still about two-thirds self-sufficient in oil, Europe about one-fifth self-sufficient and Japan totally dependent on imports. Somehow, the allocation of the burden still seems out of whack.

The most aggravating free rider, though, isn't other consuming nations. It's the direct beneficiary of our protection: Kuwait. Kuwait extracts oil from its land for a few bits a barrel. As an OPEC "moderate," it has been willing to sell this oil lately for a mere $18 a barrel. To achieve that markup, it engages in a conspiracy in restraint of trade -- flatly illegal by American standards -- with, among others, the very nation we are protecting it from: Iran. During the OPEC glory years, oil revenues gave Kuwait a per-capita GNP higher than that of the United States. It's still a very rich country. Yet kindly Uncle Sam doesn't even balk when Kuwait refuses basing rights for helicopters needed to protect Kuwait's own ships containing Kuwait's own oil.

Ah, but the leader of the free world must safeguard the freedom of lesser nations even if they are too spineless to cooperate. No? Perhaps, but sentiments like that hardly apply. Kuwait is governed by a ruling family, the Al-Sabahs, led by the Amir. There's a legislature, and you can even vote for it if you're a male from a long-settled family. As the State Department's annual human rights report tactfully described the legislature's function, it "institutionalized a degree of consultation with the ruling family and served as an outlet for popular expression."

Unfortunately, the Amir suspended the legislature a year ago and, while he was at it, suspended the law that a suspended legislature must be unsuspended after two months. Why? A "breakdown in cooperation between the executive and legislative branches." You know how it is, Ollie. The Amir also took the opportunity to start press censorship. It was already illegal to criticize the government.

There's no knowing what the current Persian Gulf operation is costing. Iranian Parliament Speaker Ali Akbar Rafsanjani, everyone's favorite moderate, may have been exaggerating when he snorted that it would be cheaper to fly the oil out. But former Navy secretary John Lehman estimates that the share of the Reagan-era military buildup specifically designed to make good on the so-called Carter doctrine -- that the United States will protect Mideast oil supplies by force if necessary -- is costing American taxpayers about $40 billion a year. The Mideast supplies something under 4 billion barrels of oil a year. That means our protection is costing roughly $10 a barrel.

Why not charge? Right now, the market seems to be valuing our protective services at minus $3 a barrel. But if Kuwait disagrees, it can certainly afford to pay up. Just to show we're not completely mercenary, I suggest a sliding scale from $10 to $5 a barrel, depending on progress toward democracy -- a dollar off for reopening parliament, 75 cents for giving women the vote, $1.50 for freedom of the press, a penny for televised Amir primary debates.

And if they won't pay up? Surely, in the free-market spirit of Reaganism, this is a sign that the service is not worth what it costs to provide.