IN the economy as well as in Iraq, the White House is aiming for regime change.

''The president concluded we needed a package of tax relief of sufficient size to move the needle on the economy,'' Pamela F. Olson, the assistant secretary of the Treasury for tax policy, said on Wednesday. ''Tinkering around the edges won't do that. Small won't do that.''

But tax relief does not begin to describe the fundamental changes the White House wants to make in how the economy and the government are run, and how revenue is raised. To achieve its goals, the Bush administration has turned to supply-side economics, which advocates removing taxes that are held to discourage people from working and investing their savings in the private sector. This may cause government to lose revenue in the short term, the argument goes, but faster economic growth will ultimately erase any deficits that result.

The experience of the Reagan administration, however, famously left supply-side theory open to debate. Though tax rates were cut across the board, military spending increases helped to create enormous deficits in the 1980's. This swamped whatever supply-side benefits the tax cuts might have had, forcing the Treasury to borrow huge sums -- money that business might otherwise have used for investments.

There is still debate among economists about whether Reaganomics was successful in the long term, and President Bush is proposing changes that dwarf those enacted by Mr. Reagan. Like Mr. Reagan, who was fighting to defeat the Soviet Union, Mr. Bush too is trying to win a war -- in this case a hot one -- while enacting supply-side economic policies. And once again, the dual pressures on the government's budget have attracted criticism.