THE BATTLE between the parties when Congress returns next month will have to do partly with money, but even more with vocabulary and blame. It is well understood on both sides that, by the time the appropriations process is over, total spending will be far above the artificially tight caps to which the president and congressional Republicans agreed in order to make the numbers in the balanced budget act of 1997 come out even.

The spending will not just wipe out the modest surplus projected in other than Social Security funds next fiscal year. Despite all pledges to the contrary, it will force the parties once again to use some temporarily surplus Social Security funds to cover other governmental costs instead of to pay down debt.

The Republicans hope to blame this on the Democrats. They intend to label the spending in excess of the appropriations caps a spending "increase," which they will say is the Democratic alternative to their deep tax cut. The Democrats are struggling to make the contrary point that the caps imply deep spending cuts, which they seek merely to offset. Their goal, they say, is not to increase spending so much as to maintain it in real terms.

The Democrats are right in this; the caps would force deeper domestic spending cuts than either party likely would -- or should -- support in the long run. But the president and Democrats are handicapped in their resistance by the fact that the president signed off on the caps two years ago, even celebrated their projected effect. For the sake of a signing ceremony, he and some of them professed support for spending limits that they knew at the time would do harm and be unacceptable. In effect, they wrote a lie into law, and they and the country are both now dogged by it.

The budget already was well on the way to balance in 1997, thanks to past policy and a strong economy. The centerpiece of the balanced budget act was not added discipline but a tax cut. To pay for it, the parties agreed to some genuine spending cuts, mainly in Medicare, some of which they may now ease. When those proved insufficient, they made some mainly paper cuts as well. Tight caps were imposed on future appropriations, but on appropriations generally, not specific programs.

The virtue of this, politically, was that the parties could claim to have cut future spending without inflicting the pain, which was left to future appropriators. The price was that they distorted the future budget debate. Because the appropriations caps were official policy, budget estimators had to assume, even knowing better, that they would be adhered to. Most of the projected surplus in other than Social Security funds over which the parties now are arguing derives from that unlikely assumption. Assume instead that appropriations simply keep pace with inflation -- no cuts in real terms in law enforcement, Head Start, highway grants, etc. -- and all but perhaps a tenth of the trillion-dollar surplus over the next 10 years disappears.

The Republicans can't afford to admit that, because they're counting on the mostly imaginary surplus to finance their large tax cut. The Democrats can't quite afford to admit it, either, since they played their own part a couple of years ago in the pretense that they now deplore but can't disown. The president is trying -- we hope he succeeds -- to fend off the consequences of a false promise that he himself joined in making in 1997 because it suited his political purposes at the time. It's a pretty ugly way to govern.