THE STYLE was earnest, rather than dramatic. The tone was characteristically flat. In his "frank talk" about inflation, President Carter was - wisely - very careful to avoid raising expectations of immediate results. The standard explanation of the current inflation is that its causes all lie in the past, and it's only their effects that keep chasing each other upward through the economy. But modern societies seem to have an inherent susceptibility to inflation, mainly because of the broad guarantees of security built into them. At best, the present American inflation rate won't be brought down quickly. Mr. Carter's remedies are designed for the long haul.

Since the government's sanctions are few and compliance will be largely voluntary, the president's job is to build an atmosphere of cooperation. That's not easy. There is residue of cynicism left by the failure of all the previous anti-inflation drives. The present effort will evoke disappointment among those people who fel a need for more drastic and rapid action. But it's hard to think of any more stringent measures that would have seemed fair to all of the very wide variety of people whose support the administration now needs.

Mr. Carter proposed only one new idea, but a highly ingenious one. He will ask Congress to enact inflation insurance for wages, to protect people who cooperate with the program. If people settle for wage increases lower than the curren inflation rate, and if the inflation rate in fact does not come down next year, those people would get a reimbursement in the form of an income-tax rebate. Since the present inflation is being driven by people's fears of future inflation, this device is a helpful inducement to moderation. In political terms it is an attempt to reassure the labor movement that Carter program will not weigh more heavily on wages than on prices or profits.

For business, there is Mr. Carter's promise to impose a tighter order on the rapidly growing volume of federal health and safety regulations.The White House is now organizing what it terms a regulatory budget. Federal agencies now are required to notify the Office of Management and Budget of the regulations that they intend to issue over the coming year. The OMB is then to review their costs, benefits and impacts on industries - and, for the first time, it will set priorities.

The first major challenge to Mr. Carter's plan is likely to come next spring when the Teamsters negotiate a new contract. Mr. Carter spoke of increasing the competition in the trucking industry. The message to the trucking companies is that, if they grant the Teamsters an outsized wage increase, they cannot rely on the Interstate Commerce Commission to follow tradition and let them pass that increase on to their customers. As for the steel industry, always a prominent symbol on these occasions, the White House mentions the possibility of relaxing the import restrictions if domestic steel prices get out of hand.

Not everyone will like this plan. But if you don't you have to answer two questions: What would you have preferred? And can you believe that, in reality, anybody would have supported your alternative? Our own judgement is that anything much stronger than Mr. Carter's program would have proved too divisive to be effective, in the present confused and querulous state of political opinion in this country. Anything weaker would hardly be worth trying. Mr. Carter warned that the outcome of this cautious effort is anything but certain. What is the proper measure of success? The inflation rate this year has been rising sharply. If it can only be made to turn around and begin to drop, that will be triumph enough for the months ahead.