When it comes to easy political responses to show you're dealing with the energy problem, there's nothing as popular in Congress these days as railing against the foreign tax credit allowed the big oil companies.

As a political loss-leader, the foreign tax credit issue has everything:

It's a way to cash in on "billions of dollars in tax breaks going to profit-heaving multinational giants." It's a chance to take a shot at the oil cartel. And it's a way to "lash" out at the "villains" of the oil shortage.

Small wonder then that in a largely symbolic vote last month, the House balloted 355 to 66 in favor of cutting back the foreign tax credit for oil companies by treating their royalty payments to OPEC as simple deductions.

The House action isn't binding. But the House Ways and Means Committee begins hearings next week on the foreign tax credit, with new demands by liberals to pare it back substantially, at least for U.S. oil companies.

And the Treasury has proposed changes that would limit the oil companies' ability to use their excess credits from drilling operations to offset income from related ventures such as shipping and refineries.

It's still not fully certain whether Congress ultimately will move this year to restrict the amount of foreign tax credits that oil companies use. The House seems primed for some sort of action, but the Senate may balk.

The difficulty is the issue still is mired in misperceptions - even by key members of Congress - both on what the tax credit does and how it is used. Most experts agree there have been abuses, but not quite the way critics describe.

There are these examples:

Contrary to the prevalent rhetoric, in most cases companies may use the foreign tax credit only to offset the U.S. taxes they owe on income earned in other countries - not on money they earn here at home.

The credit is there simply as a matter of equity. Without it, a firm would have to pay double taxes on the income it earns overseas - first to the country where it earned the money, and then to Uncle Sam as well.

Contrary to contentions by many now clamoring for "reform," the oil companies don't have the opportunity they once did to claim dollar-for-dollar credits for the royalties (disguised as taxes) they pay to producing nations.

The loophole was a serious problem in previous years, largely because the government then sanctioned it. The decision was made deliberately, in the 1950s, to help underwrite the development of Middle Eastern oil.

But over the past few years, the Internal Revenue Service has issued new rulings that have all but eliminated that opportunity. Under current rules, credits are denied for any form of taxes but a regular income tax.

In reality, there's little more that Congress can do to tighten the law any further. The Treasury issued proposed regulations last Friday providing tough new guidelines for the companies. Most analysts believe these will be enough.

Even if the law is changed to prohibit the use of the tax credit to offset royalty payments to oil-producing nations, there's no guarantee that the tightening will deprive the oil companies of any tax breaks.

Most likely, the OPEC countries simply would change their tax structure to substitute some other form of tax for the royalty payments - and the new tax probably would qualify for a credit. That's what Indonesia did last year.

There also would be little sense in eliminating the foreign tax credit until Congress also were to repeal the law allowing oil companies to defer payment of taxes on their foreign source income.

Tax experts say if deferral were not repealed, the oil companies could escape the impact of the shift simply by keeping their foreign-source income overseas - a step most policymakers would not like to see.

For all the talk about "hitting" the oil companies, many tax experts say the impact of a crack-down most - in the form of higher prices or even worse shortages.

The oil-producing countries like the present arrangement because it provides the oil companies with a steady profit that the host countries believe encourages them to drill there. The companies like the guaranteed income.

Tax experts say if the present rules were tightened significantly, one of two changes would result: Either the OPEC countries would raise prices to guarantee the companies the same profit, or the firms would cut exploration.

Neither is a happy thought.

What seems to provide the most sensible opportunity for tightening, in the view of many analysts, is the issue cited by the Treasury proposals - the problem of using excess credits to offset shipping and refinery income.

Whatever the view on the so-called royalties issue, experts say the bulk of the abuses in the past have centered here - and will continue in the future unless they're capped off.

The problem comes because oil companies typically accrue so many foreign tax credits on their income from drilling and extraction that they have far more than they need.

So they use them to offset income from their overseas-based subsidiaries that deal in shipping and refining - and just at a time when the U.S. is spending millions to subsidize domestic shipping firms.

All this isn't to say that the oil companies have been blameless on the question of abusing the foreign tax credit. Although oil company profits aren't high now, the industry is taxed lightly - though not as much as foreign firms.

The point, however, is that the issue isn't quite as simple as the critics would portray it. Socking the oil companies may make a hero out of a politician in the short run. But it could have other consequences as well.