AS A U.S. WAR with Iraq draws closer, the Bush administration's discussion of its economic plan is becoming increasingly unhinged from reality. It would be an amusing case study in the surreal nature of Washington debate if it were not simultaneously so irresponsible -- and so real. The situation is this: The administration, already facing a record budget deficit of $304 billion this fiscal year, wants Congress to enact a 10-year, $637 billion tax cut plan that by the administration's own estimates will dig the deficit even deeper. As Congress considers that course, the administration is refusing to put any price tag on the coming war with Iraq; any number would be wrong, it says, so why try? White House press secretary Ari Fleischer offered a particularly galling version of this argument the other day, telling reporters: "There is, unquestionably, a responsibility on the executive branch to provide to the legislative branch an estimate about what the war would cost, what the humanitarian operation would cost. And that is a responsibility the administration takes seriously. Because we take it seriously, I'm not in a position to speculate about what the number may be."

But administration budget experts have been doing exactly that. Newspaper reports last week said they are considering ranges between $60 billion and $95 billion; President Bush was briefed about the costs. The uncertainty over the precise figure may be a legitimate reason not to have included war costs in the administration budget request of last month. But that is no excuse to refuse to discuss, or for Congress to fail to consider, the broad range of possible costs in the context of whether the United States can also afford Mr. Bush's tax cuts. Ignoring the war would be like parents with young children deciding not to save for college because they don't know which school their children will attend. This much is clear: The cost of the war will be far greater than zero. Moreover, as Defense Secretary Donald H. Rumsfeld testified last month, the administration is racking up a monthly bill of about $1.6 billion for various terrorism-related activities outside Iraq, and it has already spent more than $2 billion getting troops in place; those sums aren't included in the budget either.

The administration wants Congress to pass the tax cut -- or, failing that, at least a budget resolution that etches a number for the tax cut in stone -- before it shows its hand on the war. Then it can come forward with a supplemental spending request, after hostilities have started, that Congress will have to honor. There is more at stake here than whether lawmakers will allow themselves to be played for the fools that the administration apparently takes them to be. It's whether the country can afford what the president is proposing. The administration dismisses all questions of this sort by incanting the phrase "economic growth." But the administration's own economic models make clear that, whatever economic growth the tax cut may produce, it will not pay for itself. Tax cuts have a price. So do wars. Congress needs to take both into account before it acts.