In a concerted attempt to calm the fears in Europe of nuclear war, NATO foreign ministers led by U.S. Secretary of State Alexander M. Haig Jr. said today that significant progress has been made this year in strengthening the position of the Western alliance and establishing a dialogue with the Soviet Union that could reduce tensions and nuclear armaments.

"It would appear to be a year," Haig told reporters after the semiannual meeting of the North Atlantic Council here, "in which we have come out in a substantially better posture than when we entered it."

He cited the absence of any new "blatant interventionist activities by the Soviet Union," like the invasion of Afghanistan, his "repeated meetings" with Soviet Foreign Minister Andrei Gromyko, the start of U.S.-Soviet talks to reduce intermediate-range nuclear weapons in Europe and progress toward beginning similar talks on reducing long-range strategic nuclear weapons.

This upbeat assessment, however, was coupled by Haig with reiterations of U.S. concern about "a lack of restraint on the part of the Soviets" in shipping arms to Cuba for use in Central America and U.S. determination to take "minor steps" against "international lawlessness" by Soviet-armed Libya.

But Haig's emphasis in the ministerial meetings and press conferences with reporters here was on optimism about the new East-West dialogue, a theme echoed by some European foreign ministers and NATO Secretary General Joseph Luns.

Luns and the British foreign secretary, Lord Carrington, expressed satisfaction at how quickly the Geneva negotiations moved from technical preliminaries to substantial bargaining on nuclear arms, according to a secret report the foreign ministers received here from U.S. negotiator Paul Nitze.

The foreign ministers appeared to be working to dispel European perceptions of a dangerously confrontational approach by the Reagan administration toward the Soviet Union that has fueled the growth of the influential European nuclear disarmament movement. President Reagan's speech in November on the U.S. approach to negotiations on reducing both intermediate and long-range nuclear weapons is regarded by many European diplomats as a potential turning point in changing that perception.

Haig and some European diplomats explained U.S.-European differences on Libya, which the U.S. has accused of planning to assassinate U.S. officials, as a case of the United States taking actions it believed necessary to deal with a problem particularly affecting it without either cooperation or criticism from the Europeans.

Asked after he met with Haig today whether Britain shared his assessment of Libyan intentions and what ought to be done, Carrington said only that "the Americans obviously are very concerned . . . I was impressed by their feelings."

But West German officials joined those of Italy and France in expressing skepticism. A senior West German diplomat said efforts should be made to turn Libya into a nonaligned nation rather than push it into the Soviet camp. Italy and West Germany have extensive trade with Libya and sizable numbers of citizens working there.