WHILE THE NEW prohibition against offshore drilling will protect much of California and Florida, it does not necessarily mean less oil washing up on American coasts. Unfortunately, it probably means more. No one can know how much oil might have been pumped from those offshore wells, but whatever the amount, it will be replaced by imports arriving by ship. The offshore rigs have a pretty good record of limiting spills and cleaning them up. The tankers do not, as all the recent disasters have demonstrated.

It's another example of this country's disjointed and contradictory attitudes toward energy and the environment in general. President Bush has provided a degree of protection to long stretches of much-cherished coastline. But it would be more reassuring if there were any reason to think that he, or anyone in his administration, had a clear strategy in mind for dealing with the consequences of decisions like this one.

Over the past couple of years this country's consumption of oil has been falling slightly. But domestic production has been falling much faster, and the result is that the United States is now importing half of its oil supply. That proportion is likely to rise steadily through the 1990s. The increase in air travel is raising the demand for jet fuel rapidly, and among new cars, the improvements in fuel efficiency have tapered off. The increasing dependence on seaborne oil is the reason for the rising numbers of spills.

A prohibition against drilling off certain coasts of great aesthetic value is entirely reasonable, but the price of that protection isn't getting enough attention. A drilling ban ought to be accompanied by conservation measures ensuring that the effect is not merely to increase the flow through the nearest oil ports. There are many ways to do that, the most efficient and fairest being a tax on gasoline and aircraft fuel. That's the section of Mr. Bush's statement that's missing.

It's characteristic not only of Mr. Bush's thinking about environmental protection but of Americans' in general. Everybody wants a pristine seashore, and everybody wants to drive there as frequently and cheaply as possible. Is there a contradiction here somewhere?

While protecting the environment is necessary and entirely desirable, it isn't free. One of the greatest dangers to the environment is this country's refusal to use public policy to push serious conservation -- meaning, among other things, eliminating the demand for the oil that those offshore wells might have produced.