Energy, foreign affairs, inflation and domestic politics are all mixed up in the decision the president is now mulling about decontrol of domestic oil. The links between each of these subjects are complex and the statistical evidence uncertain.

The politics are obscure. So it seems useful, before setting out a preferred line of action, to consider the connected issues one by one.

As regards energy, a strong case could be made -- and has been by Energy Secretary James Schlesinger -- that the president should exercise the authority he will acquire as of June 1 to decontrol the price of domestically produced oil. By raising prices of oil and competing energy sources, decontrol would promote conservation.

By raising incentives, it would increase production -- not only of oil but also of other energy sources. But just how much more would be conserved and how much more produced is not clear.

International considerations -- as Secretary of State Cyrus Vance and Treasury Secretary W. Michael Blumenthal have made plain -- reinforce the case for decontrol. The major oil-exporting countries and the major oil-importing countries both resent the huge U.S. consumption, which is now fostered by controls on domestically produced oil. The exporting countries would probably go easier on raising prices if they were persuaded the United States was finally moving to meet its energy problem -- especially since a threatened shortage might be averted.

Japan and the major importing countries of Western Europe would also be relieved. By decontrol, the president would build confidence that he was working to meet problems of energy and inflation. That would lead to a stronger dollar and important benefits for this country at home and abroad.

With respect to inflation, a one-time decontrol might kick up the consumer price index by as much as eight-tenths of a point. That heavy shot could be eased by phasing out the decontrol over several years -- perhaps until 1981, when the authority to control runs out entirely.

Even so, an announcement of decontrol would be bound to have an impact on the big labor contracts coming up for settlement -- especially that of the Teamsters, which is due to expire on March 31. With inflation already running at 9 percent, it will be extremely difficult -- as the president's chief inflation fighter, Alfred Kahn, has regued -- to hold the contract within the 7 percent increase now set by the wage-price guidelines. A big Teamster settlement -- a visible breach in the guidelines -- might pave the way for a round of similar increases that could trigger a new burst of inflation.

But it may be that the increases in fuel and food costs have already raised the consumer price index to the point where a fight on the guidelines now would necessarily be a losing fight. It might be preferable to fudge the issue with the Teamsters -- perhaps by giving them higher cost-of-living benefits -- to save the guidelines for a fight later on, when inflation should be moderating because of the general cooling-down of the economy.

With respect to domestic politics, the sharp issue is fairness. Along with all other corporations, the big oil companies are showing very high profits. As the president's chief domestic adviser, Stuart Eizenstat, has pointed out, decontrol would increase their profits at the expense of the poor people and minorities so important to the Democratic Party. To be sure, big gains could be taxed away at the wellhead or in a windfall-profits tax. But such taxes would require congressional action. The oil lobby and the Congress may well be strong enough to block any new tax, and the president would at least share some of the blame with the Congress.

Of course, the president could make decontrol contingent on congressional passage of new taxes. That way the monkey would be more squarely on the back of the Congress. But if the Congress still did nothing, the president would catch most of the blame -- as he has recently -- for not having an effective energy program.

My own preference would be for phased decontrol by 1980, with a provision for total decontrol as soon as Congress enacted a windfall-profits tax. In that way the president would ensure himself of having a workable energy program, with the multitude or internal and international benefits that follow in the future. He would cushion the inflationary impact and make a goodfaith effort to achieve fairness for constituents who in the end will probably stick with the Democratic Party.

Whatever he does, however, the president should not pretend that he has found the perfect program that will settle all issues once and for all. The big trade-offs are truly hard -- so difficult, in fact, that a mere mortal has to wonder why anyone would want to be president.