Even if the allies chip in the $51 billion they have promised to support the costs of waging war against Iraq, the indirect costs of that war are going to be a major burden on U.S. taxpayers for years to come.

Increased veterans expenses and replenishing expended munitions stockpiles will require several billions. But the real money, hidden like an iceberg, will be for weapons systems and defense concepts whose need has now allegedly been proved by combat.Two examples of indirect war costs came in President Bush's budget message. He and Defense Secretary Richard Cheney asked Congress to step up funding for the B-2 bomber and the Strategic Defense Initiative on grounds that Operation Desert Storm had proved the need for them.

Cheney said the performance of radar-evading Stealth aircraft like the B-2 had been vindicated in the air war over Iraq. And both he and Bush contended that the amazing success of the Patriot missile defenses in Saudi Arabia and Israel had demonstrated how vital SDI would be against proliferating, Third World ballistic missiles.

A month ago, the odds that either of these systems would ever be built and deployed were probably in the neighborhood of 2-1 against. The House voted to kill both of them last year, and the Senate cut them back severely in the first wave of defense reductions that greeted the end of the Cold War.

Now the war has given them a new breath of life. The potential cost for both systems could exceed $200 billion - several times the direct cost of the war in Iraq, even if it stretches into midsummer.

One casualty of this war may be the tougher, more businesslike approach to military contracts that was beginning to take hold under Cheney.

The defense secretary, a veteran politician as well as an expert on military affairs, cracked the whip before the war began on two contractors who had mismanaged the Navy's A-12 fighter program. Not only did he cancel the contract when costs soared above the agreed price, but he fired the admiral who was managing the mess.

A few days ago, however, McDonnell Douglas and General Dyamics demonstrated the kind of clout major defense contractors have in wartime. The Defense Department announced that it had reduced, for reasons that are not clear, the sum those two contractors owed the government for A-12 work unperformed from $1.9 billion to $1.3 billion. Moreover, the department said it would not try to collect from the contractors immediately, but would wait until the end of a court process that could drag on for years before sending them the bill. Interest payments on that debt, in the interim, will be born by the taxpayers.