THERE'S NOW beginning to be a real possibility that President Carter's energy bill will collapse altogether. Until the end of last year, it seemed to be only a question of the compromises that would be made, and the delays that would have to be suffered. It seemed certain that the bill would eventually be passed. But that certainty is rapidly disappearing into the fog that surrounds every other aspect of this entangled and deadlocked bill.

If Mr. Carter wants a bill that bears any faint resemblance to the one he proposed last spring, he is going to have to begin negotiating directly and explicitly with the congressional leaders. If he still thinks it is as urgent as he asserted last April, he is going to have to drop his vague formulations of what would be acceptable and begin to work earnestly to rescue what he can.

There is now talk, in and around Congress, of abandoning the effort altogether - or perhaps enacting only the minor provisions of the bill, without the central sections on the pricing and taxing of oil and gas. An increasing number of people, on all sides of the question, have begun to think it might be safer to settle for nothing than to risk getting something worse.

The administration is beginning to get embroiled in its other necessities. Under the original strategy, the energy bill with its broad taxes was to be enacted last year, and the tax cut to offset them was to come along this year. But the tax cut is pushing ahead of the energy bill on the timetable - and the administration is having to make arguments in behalf of tax reductions that cut painfully against its energy bill. If it's necessary to cut taxes in order to keep the econimy expanding , why isn't it dangerous to increase taxes on oil and gas? There's an answer - most of the fuel taxes would take effect only after a couple of years - but that's apparently a bit too intricate to be well received.

After all, the argument goes, the present law gives the administration considerable latitude to raise oil prices and enforce conservation. Anyway, it continues, industries are already beginning to switch to coal, so why bother with all those elaborate new regulations? Why not just let matters take of themselves?

No one can foretell the cost that might be inflicted on the country by letting matters take care of themselves. It's worth remembering that the oil crisis four years ago threw this country into the most severe recession - and the highest unemployment - of the past generation. This country still has not fully recovered. American dependence on foreign oil is too great to permit any rapid reversal. But it would be irrational to refuse to make a beginning, merely because the process of change is a long one.

There are severe dangers in the let-it-slide philosophy. Failure to enact a bill would leave wide open all of the crucial questions of pricing and costs, compounding the sense of uncertainty in all the industries that produce and consume fuel.This uncertainty holds down investment, which is in turn a drag on economic growth and productivity.

But there's more at stake than economics and money. If the energy bill now collapses, the political penalties would be incalculable. Abroad, our alies would regard it as a dismaying failure of national purpose. They would interpret it - and who could argue? - as evidence of a country too lazy, or too confused, or too self-satisfied to keep its promises of leadership. More important, Americans would know that Mr. Carter had lost control of the one bill that he himself had designated central to the nation's security and prosperity. Some people would assume, no doubt, that energy had ceased to be a subject to worry about. Others, looking deeper, would see the dismaying truth that their government had failed, and given up, on the most pressing of its present responsibilities.

There is still time for Mr. Carter to intervene, break thecongressional deadlock, and work actively with the leadership there to bring a bill to enactment. There is still a little time - but time is not working in his favor.