Thatcher, Unlike Reagan, Shows the Staying Power of a Will Wed to Principle

LONDON — Margaret Thatcher is not only the most successful but also the most astonishing political leader in the Western world. As of this week she is the longest continuously serving British prime minister of this century. Yet she is not at all the kind of politician who usually holds onto power for a long time--the cautious conciliator, who keeps the voters sweet by taking care to give offense to the fewest people possible.

The previous record-holder--Herbert Henry Asquith, prime minister from 1908 to 1916--was known for the maxim “Wait and see.” It symbolized his gentle caution. If Thatcher were to use such a phrase it would be considered a threat, not a mark of indecision. She is the most radical prime minister whom Britain has had in this century, and the longer she remains in office the more radical she becomes.

In this respect she presents a sharp contrast to President Reagan. The two of them came to power at much the same time and with much the same objective. They were both right-wingers who believed that the role of the state had increased too much over a period of years, that the incentives for enterprise had been diminished and that not enough faith was placed in market forces. This was the fault of successive administrations, of those run by their own party as well as by their opponents. So they both took office determined to reverse the direction in which their countries had been run by governments of all political complexions for many years before them.

They both started off in that fashion. But Reagan has never been prepared to make the really tough political decisions. He has not been willing to choose between incompatible policies. That is why the U.S. budget deficit has been soaring while Britain is in sight of a balanced budget.

Reagan has fought most tenaciously for lower taxes, but that is hardly likely to make him unpopular politically. The longer he has remained in power, the more responsive he has become to public opinion. The leader who began by rearming furiously is now the most eager to negotiate disarmament.

Throughout his time in office, and of ever greater importance, there has been the charm of his personality--reassuring and friendly. Who could dislike a man like that?

Thatcher’s style is very different. She is abrasive. She enjoys argument and confrontation. She is admired for her strength and courage rather than loved for a sweet nature.

Her determination to change things in Britain is even greater now than when she became the prime minister in 1979. Not that she was a timid or slothful leader in her first two terms. She went further than anybody had expected her to in cutting down the power of the trade unions and in selling publicly owned industries back into private hands-- privatization , as it is termed.

She had to take risks along the way, especially in tightening the law on trade unions and in standing up to the miners’ strike in 1984-85. But these objectives were not unpopular in themselves. The unions were thought to have become too powerful, even by a majority of their own members. Publicly owned industries were considered to be often inefficient and inconsiderate to their customers.

The doubts were over whether it would be possible to bring about change without creating chaos. Was it realistic to try? But when Thatcher succeeded, she had public approval.

Now she has embarked on a still more daring course. She is seeking changes in the welfare state--in education, in housing and in financing local government--whose very purpose is controversial. The doubts now being expressed are not simply whether she will succeed but whether it would be right for her to succeed.

Such resistance is inevitable once she gets into the sensitive social areas in which reform is needed--and it is certainly necessary in education and housing. As the strong leader of a government with a large parliamentary majority, she will probably be able to bring it about. But in doing so she is taking a political risk.

She is bound to make more political enemies as she pushes this legislation through. For the moment that will not matter, because her position is so secure. But it could make it harder for the Conservatives to win the next election if they are faced with a credible challenge by then.

Thatcher must know this as well as anyone. What makes her so remarkable is that she not only continues to gamble; she also increases the stakes in her determination to change Britain as she wants.