THE STRENGTH of President Carter's energy plan is that it sets a clear course for the next decade and beyond. Oddly, that seems to be the point on which it's being most severely attacked - that it doesn't do anything right now. It's true, but only in the sense that, for the next year or so, it will be the recession rather than policy that cuts American oil consumption. One way or the other, Mr. Carter's import limit means that by the beginning of next winter American oil imports will be running significantly lower than at the same season last year, regardless of availability abroad.

Across three administrations - Nixon, Ford and now Carter - there has been a partern of grand strategies at first and then, as the political pressures rose, shorter and shorter perspectives. By last May, Mr. Carter himself was giving a very fair imitation of a man desperate to end the gsaoline lines on any terms at all as long as they ended quickly. He was leaning on the Saudis to increase production, and he was leaning on the oil companies to bid against our allies in the spot markets. Those were dangerous tactics, threatening to both the producers and the other consuming nations. Now Mr. Carter has corrected himself. Amidst the turnmoil over policy and personalities that Mr. Carter has generated in this past week, it is important not to lose track of this one central commitment that was both courageous and right.

Staying within Mr. Carter's import targets will be difficult, but not impossible. His expectations for the production of synthetic fuels are certainly too high, and Congress needs to approach them with great caution. The president's hopes for solar energy are also likely to prove optimistic. But, conversely, he underestimates the enormous savings available through conservation.

The import limits serve as a signal to the country that oil supplies will be tight over the years to come, and prices high regardless of OPEC's strategies and producers' shifting purposes. For consumers, from private households to large industries, it is a warning to find ways to use it more efficiently, or to find equipment that will run on some other fuel. For the American suppliers of both fuel and the equipment that generates heat and power, it is an invitation to push forward a great variety of technologies that have been tested in the laboratory, but not yet at industrial scale.

But conservation, and new energy technologies, require the push of a higher price. The most serious error in Mr. Carter's oil policy is precisely there, in his adamant refusal to decontrol gasoline prices. If he does not reverse himself, this error will undercut everything else that he tries to do about oil. His next good opportunity to deccontrol gasoline will be in the fall, when the vacation season ends. It's essential to do it before next summer, because the import limits mean that supplies will be tight again then.It's better to have gradually rising prices than shortages and long lines.

The country has now gone through the second cycle of excessive oil demand, leading to shocking increases in foreign oil prices, leading to recession. Five years ago, under the crippled Nixon administration, the country did nothing to prevent a repetition. This time, Mr. Carter is urging the country to free itself from the oil trap. Nobody likes higher fuel prices. But keep it in mind that as the prices go up, they will represent an insurance premium against a third oil-induced recession - painful and damaging - in the early 1980s.