The British miners' strike grinds hopelessly along, producing much violence but little progress toward a settlement. Eleven years ago, a similar strike brought down Edward Heath's Conservative government in a matter of weeks. This year, after eight months of the strike, Margaret Thatcher's Conservative government remains as firmly in power as ever. What accounts for that vast difference?

Economists say that rising unemployment has cowed the British labor movement. But that's only a small part of the answer. The internal balance in British politics has shifted, and the unions in general have lost both power and moral authority.

The earlier standing of the miners' union goes back to a series of brutal collisions between mine owners and miners in the years between the two world wars, swinging public support strongly in favor of the miners. When a Labor government nationalized the mines immediately after World War II, the opposition was minimal. Whatever the friction between them, the Conservative Party, like most British voters, accepted the unions in the postwar years as a legitimate political instrument of the working class.

All that changed in the 1970s. The miners' union was one of the less obvious victims of the oil crisis of 1973. The enormous increase in oil prices made offshore production profitable in the North Sea, and British oil production in turn made coal less essential. Next, the oil prices set off severe inflation that, as in other countries, increasingly frightened voters. In Britain it was aggravated by the demands of strong unions and, as voters began to blame them for it, the leadership of some of the unions migrated sharply leftward.

Ever since it first moved toward a strike last March, the leaders of the miners' union have adamantly refused to allow a strike vote among their members. That refusal has drawn attention to some of the less appealing implications of the leaders' Marxist convictions, and explains the extremely tepid support that they have been getting from the rest of the labor movement. But, however radical in its politics, the union is simultaneously extremely conservative in its social aims of preserving miners' jobs even in the most worn-out mines -- as the union puts it, preserving the jobs for the sons and grandsons of the present miners. Mrs. Thatcher undoubtedly is correct in observing that the rigidity of that demand, in defiance of all economic limits, is not consistent with the rising standard of living for Britain.

As the unions' confusion filters up to their political arm, the Labor Party itself becomes increasingly distracted and confused. It leaves Mrs. Thatcher stronger than ever. And it leaves the British government destitute of the vigorous and coherent opposition that any government needs.