Poland's leaders watch Walesa closely as they weigh an end to martial law

Lech Walesa - as buoyant as ever and seemingly undefeated in spirit after 11 months of internment - has quickly affirmed his undiminished commitment to the reform and union agreement he negotiated with the Polish government over two years ago.

But he also offered to work in ''friendship'' with the government for the reconstruction of Poland.

Which will it be - leader of an independent union or friendly supporter of recent government initiatives?

For its part, the government of Gen. Wojciech Jaruzelski is clearly waiting to see what Walesa does as a ''private person.'' For the moment it regards him - in the words of the official news agency - as the ''former leader of the former union Solidarity.'' There is only a hint that there might be a future role for him to play.

Walesa's gesture was made in a news conference with the foreign press at his Gdansk home, only some 12 hours after a reunion with his wife Danuta and their seven children.

''I remain faithful to the agreement (of August 1980 with government),'' Walesa said, ''and I will not depart from its spirit.'' But as he had done during the turbulent events of 1981, he also acknowledged that in Poland's present economic plight, limits on the union's role might be necessary.

It is being taken for granted here that martial law will be lifted when the Sejm (parliament) meets in special session Dec. 13 - exactly one year after military rule was imposed and Solidarity suspended.

Everyone is asking: What will Walesa do? Will Gen. Wojciech Jaruzelski accept his proposal for talks? What is his view of the labor unions prescribed in the new law? (The law provides for independent self-governing unions within individual workplaces.)

General Jaruzelski has affirmed the ''independence'' of the new unions and said they will be ''what the working people want them to be.'' One may assume that for a majority of workers - even those who ignored the underground strike call for Nov. 10 - that means a union movement in which Walesa will have a part to play.

On that specific point, General Jaruzelski has just told a British reporter that Walesa's future will depend on ''what he does now that he is free.'' He would judge him, the general said, by his ''future activity, by the discipline he displays, by his public utterances - especially to the Western press.''

Walesa has taken care in his first two public statements since his release not to overstep the boundaries Poland's military rulers have in mind:

''I want to work for the development (of Poland) in a spirit of friendship on the road to social peace so that we may realize what it is possible to realize in the situation in which we find ourselves.

''I must confront my ideas with reality,'' he said.

He declined to comment on the union underground directed by the handful of leading activists who eluded police capture when martial law was imposed. He had had a premonition it was coming, he said, and he might have escaped, too.

''I didn't try,'' he said. ''I wanted to take the responsibility on myself to stay to the end - as a responsible Pole who lost a battle that could not have been won.''

It was the kind of statement likely to commend itself to Poland's disciplinarian-minded soldier leader.

It is just about a year since Jaruzelski, Walesa, and the Polish primate, Archbishop Jozef Glemp, met in a last effort at dialogue before martial law. Some informed quarters here indicate that Walesa's letter a week ago to Jaruzelski was drafted on lines counseled by Pope John-Paul II and brought to Warsaw by the primate.

It is one of several indications of how firmly the Roman Catholic Church backs any attempt to renew dialogue for a ''national front'' - government, church, and workers - akin to the one first floated in November 1981. It could be the next thing to happen here, either before or after martial law is possiblyended Dec. 13.