SAUDI ARABIA's decision to pump an extra million barrels of oil a day derives from its "historic friendly relationship with the United States," the White House says. Nonsense.The decision flows from an assessment of its own economic and political interests. The truly "friendly" act would have been to pump a larger quantity of oil, at a price closer to the cost of production. For the Saudis to join in raising the price of oil a crushing 61 percent in this year aline, and then to be thanked for agreeing to sell more of it, makes the head spin.

Yes, at his time, the United States needs the oil. But Saudi Arabi needs if not the cash, then the protection, reassurance and good will it hopes it is buying with the extra supply. It is enough for the United States to pay once, in dollars. It is bad police to accept uncritically the notion that it must pay a second time, in "friendship."

There are at least two reasons why this is so. First it feeds the disposition among Americans to avoid the hard choices that Jimmy Carter is reportedly weighting at Camp David. A nation schooled to look abroad for its next million barrels of oil is a nation seemingly bent on digging itself deeper into a hole. Saudi friendship is a convenience, even a necessity, for the United States at a moment when it is wallowing in uncertainty, but the convenience works against the larger need for discipline.

Moreover, it is subject to change. The president unwittingly made the point bt saying he had received Crown Prince Fahd's personal commitment on the proudction jike. What is the value of a personal commitment from one member of the fractionated family that currently runs Saudi Arabia? It will take a few months, but only a few months, to tell.

The second reason "friendship" is poor foundation for policy is that it invites the Saudis to ask for payment in political kind -- specifically, in American pressure on Israel to accommodate the PLO. The Saudis seem to be getting more explicit in this regard. It is their privilege to ask. But they should not be accommodated out of friendship.

The United States has under way a Palestinian initiative that is the most serious and promising of any launched from any quarter in 30 years. The Saudis, whose descreet assistance could be of great value, have chosen to obstruct the initiative, undermining the very cause they profess to hold dear. For oil, the United States must make certain adjustments. For friendship, it must wait for another day.