CONGRESS IS finally having to confront the fiscal reality from which it has fled all year. The projected surplus in other than Social Security funds for the fiscal year ahead is already gone, or shortly will be. They've spent it, and before they're done, will spend still more, thereby also dipping into the Social Security surplus they have pledged to protect.

Some of the spending will be excessive; the bidding war for farm votes threatens to become particularly obscene. But most of it is altogether ordinary, legitimate, "necessary" if one judges by the expectations placed on modern government. The problem is not that the spending is too high but that the projections of spending that Congress is now in the process of breaching were too low.

They were based on a false promise by the president and Congress in the so-called balanced budget act of 1997 to make deeper cuts in most domestic spending than either party is ultimately prepared to vote for -- nor should they be. In the aggregate, cuts of more than a fifth in real terms would be required in an array of programs from federal law enforcement and air traffic control to highway grants and maintenance of the national parks. They'd do genuine social harm; they won't happen because they shouldn't.

If they don't, most of the projected surplus disappears, not just next fiscal year but into the future. The funds the Republicans are counting on to finance their tax cut will not materialize. That's the reality that is dawning -- and that's why they are going to such lengths to continue to pretend to stick to the phony spending promises -- in which, we note again, the president joined -- even as they breach them. They can't afford the truth because the truth means that the country can't afford the tax cut.

The Senate has voted more than $7 billion in "emergency" farm spending. The emergency designation means the spending doesn't count as a breach of the budget rules, but spending is spending; the money has to come from somewhere. The farm aid by itself will consume half the projected surplus. By designating the census an emergency, they've eaten up another fourth. They've added billions more than yet acknowledged to next year's likely defense spending as well.

They have meanwhile artificially depressed other spending figures, pending a budget deal with the president later in the year. Both houses have passed appropriations bills for foreign operations a fifth below the president's request. The bills would "seriously impair the president's ability to conduct an effective foreign policy," the White House has said in warning of a veto. The multilateral development banks and aid to the states of the former Soviet Union are among the particular casualties. It's fair to assume the appropriation will be increased before the year is over, as it should be.

The veterans' health budget could use some cutting, but it is the site of another bidding war. The programs have been protected from cuts by "borrowing" from funds that had been set aside for the labor, health and human services and education bill. That one, which Republicans have been saving for last in hopes the Democrats will join in bailing out their favored programs, is billions in the hole. The veterans' bill remained tight even with the borrowing. To keep it within the limits required to finance the kind of tax cut they want to grant, Republicans were forced to cut housing programs for the poor as well.

The veterans' bill offers a tidy illustration of the principal work of this Congress thus far. The financing of a tax cut that would mainly benefit the better-off consists of accounting illusions whose effect would be to force the government back into a policy of borrow-and-spend, plus some spending cuts, including programs for the poor. They're faking the legislative process. They know they're going to have to do most of it over, because the numbers don't add up. Meanwhile they posture and aim to score political points. They go home for the rest of the summer today -- not soon enough, not long enough either.