A COAL STRIKE, in a country that is trying to shift as far and as fast as possible from oil to coal, raises an inevitable question. About four-fifths of American coal production is burned by the electric utilities. How much should you worry about coal supplies and the power that coal generates?

The answer is that you don't have to worry much -- for the present. The utilities, which tend to be careful about these things, have larger stockpiles today than they did in late 1977, when the last major strike broke out. That one ran 111 days through a long winter, but never seriously affected the availability of power. The next couple of months are, luckily, the season when both furnaces and air conditioners are off and the utilities carry a relatively light load.

One immediate effect of this strike will be to accelerate the development of coal production in the western states. There the coal is mined from open pits, and few of the people who work in them belong to the United Mine Workers. The western miners never joined the last strike, and are not going to join this one.

But if there's little reason to fear dim-outs this spring, it is necessary to feel a degree of concern for the relationship between the miners and the union that represents them. This strike is the result of the vote in which the miners overwhelmingly rejected a new contract that the union leadership thought it had negotiated successfully. After many bad years, the UMW has pushed new people to the top, and the prospect for strong, conscientious representation seemed more promising this winter than it had for a very long time. Even after this repudiation of the contract, it's clear that things have been moving in the right direction. The incidence of wildcat strikes and disruptions has dropped dramatically over the past several years.

But the old grievances and suspicions fade slowly. While the union will now try to work out another contract, the mine operators are in no great hurry to accommodate them. As time passes, the costs will begin to rise -- first to the miners, then eventually to the operators and their customers. In an industry where there has been notable improvement in working conditions, wages and labor relations over the past decade, it would be a great misfortune to slide into a tradition of a costly strike as each contract expires. It's not the fear of immediate power failures that makes this strike a misfortune, but its meaning for the stability of an industry on which the country must increasingly depend.