WITH AN enormous budget deficit now clearly in sight next year, the federal government has no possible way to get it down to the legally required target. Under the law, the alternative is to allow automatic spending cuts to do the job. That's now impossible. The automatic cutting formula would reduce the Defense Department's outlays by more than $50 billion -- including a reduction of one-third in the money for operations and maintenance -- at a time when it is engaged in airlifting tens of thousands of troops to Saudi Arabia.

Once again the president and Congress are going to have to rewrite the Gramm-Rudman-Hollings Act to accommodate the oversized deficits that they have been unwilling to manage rationally. That will be an opportunity for the people who want to abandon all limits on the deficit and ignore it -- and there are plenty of those people on both right and left. It's also an opportunity for those people -- fewer, but braver and more sensible -- who are going to try again to get a grip on the deficit and put it on a downward track.

President Reagan, President Bush and successive Congresses wasted their opportunities to get the budget under control in the times when it would have been easier. When the economy was growing sturdily, when oil was cheap, when the world was peaceful and serene, they played games with the numbers, prevaricated and delayed. Now Mr. Bush and the congressional leadership are going to have to tackle the deficit with the possibility of either recession or war looming immediately ahead of them.

Both the White House and the Congressional Budget Office are warning that, under present policy, the budget deficit will be at least $230 billion in the fiscal year starting Oct. 1 -- compared with about $195 billion this year, and $157 billion last year. A recession next year would send it far higher, and if Iraq starts a war the consequences in dollars, as in every other respect, would be incalculable.

There's going to be a powerful temptation in high places to use the possibilities of war or recession as twin excuses to take a holiday from the budget deficit and let it fly. That would be extremely dangerous. If the world thinks that the U.S. government is unwilling to come to terms with its budget, that will make either a war or a recession much harder to fight. Either would require heavy borrowing by the government. Lenders' uneasiness is already being reflected in interest rates that are high and rising. In an uncertain time, the government has no higher priority than to get a grip on its budget, raise taxes, and gather its financial strength for the tests ahead.