SAUDI ARABIA is letting the world know that it will continue to balance the oil markets, keeping its customers' welfare carefully in mind. The Saudi authorities said this week that they are proceeding to take their production back up during the next several years to 10 million barrels a day, nearly twice the level of last summer, before Iraq invaded Kuwait. The purpose of the disclosure was to remind their allies, beginning with the Americans, why those allies have troops sitting expensively in the Saudi desert and warships in the Persian Gulf. The message is that the defense of Saudi Arabia may cost a lot of money, but it's not a bad investment.

That's probably true. It's also true that stabilizing oil prices isn't the only reason for American soldiers to be there. A larger one is Iraq's hunger to dominate the Middle East and its demonstrated willingness to use its missiles and forbidden weapons for that purpose. But Saudi Arabia wants to reassure its defenders that, even in narrowly financial terms, they will not lose by preserving Saudi control over the world's largest pool of oil.

Unlike the other leading oil producing countries, Saudi Arabia, with its minimal domestic requirements and its enormous accumulated wealth, has wide discretion in deciding from month to month how much to pump. After the Iranian revolution in 1979, when Iranian production dropped, the Saudis quickly brought production up to nearly 10 million barrels a day. By 1985, with production rising in other countries in response to sky-high prices, the Saudis' production was down to a third of the 1980 level. Now it's rapidly coming back up.

That's welcome, and it will mitigate the impact of the Iraq boycott on the world's economy. But it's necessary to keep firmly in mind that Saudi interests are not precisely the same as American interests. The Saudis understandably want their friends -- and particularly the United States -- firmly impressed with the absolute necessity of defending them. But the United States and all other oil-importing countries know that they need to organize their energy requirements to allow them -- in the extreme case -- to do without the Gulf's oil.

The Gulf region is desperately unstable in every political and military sense. The United States cannot allow itself to remain in a position in which, regardless of any other responsibility or any other circumstance, it is imperatively required to defend Saudi Arabia and its government. It must make itself free to do so not out of necessity but by choice.