CONGRESS has confounded expectation and passed an airline smoking ban: no one will be allowed to smoke on any domestic flight of two hours or less. Antismoking lobbyists had been after such a limitation for years, arguing that it isn't enough to separate airline passengers into smoking and nonsmoking sections. Airplanes recirculate the same fouled air everywhere in the cabin, they say, and flight attendants must breathe that air for hours on end. But efforts to pass a ban always foundered until last winter, when a couple of influential reports -- one from the surgeon general and one from the National Research Council -- gave new backing to the idea that cigarettes endanger nearby nonsmokers as well as those actually smoking. This new concern with the dangers of "passive" or "secondhand" smoking has brought a torrent of new initiatives to ban smoking in hospitals, government buildings, restaurants and other places. Despite strong opposition from the representatives of tobacco-growing states, the House in July and the Senate in October also responded by narrowly passing versions of an in-flight smoking ban.

Both versions represented substantial compromise from the ban on all flights some advocates wanted -- one which, though its health benefits might have been greater, would have imposed a tremendous burden on those smokers who have been unable to quit. The two-hour compromise covers 80 percent of domestic flights -- including the heavily used shuttles between New York and Washington and Los Angeles and San Francisco -- while causing no more hardship to smokers than going to a movie does. The Senate, where tobacco interests were stronger, added a provision that the ban would expire in two years unless expressly reauthorized.

The provision ended its journey as part of the gargantuan year-end continuing resolution last week. But it proved resilient even amid the confusion surrounding the giant budget bills -- which tobacco lobbyists had looked on as their last opportunity to snuff out the ban entirely. Having weathered the fuss, it may well furnish a model for further moves against public smoking -- both as an example of reasonable compromise and as witness to a level of agreement on the danger of passive smoking that was unlooked-for only a few years ago.