'WarGames' -- big issues and teen-age heroics.

John Badham is the busiest filmmaker around, with two shiny new pictures to his name - ''WarGames'' and ''Blue Thunder'' - and both looking like major hits. He certainly knows his business: how to catapult the action scenes, build suspense with razor-sharp editing, pull extra mileage from understated performances.

He even strives for deeper meanings. ''Blue Thunder'' posits a sinister political plot as the sparkplug for its frantic (and endless) foot, car, and helicopter chases. ''WarGames'' tackles the formidable subject of nuclear war, treating the worldwide balance of terror with a blend of wry skepticism, homespun philosophizing, and blunt humor.

Of the two, WarGames is by far the better movie - not a ''Dr. Strangelove'' for the '80s, but playing in the same ballpark. If anything can make a dent in the ''Return of the Jedi'' bonanza, all signs point to this canny mixture of big issues and teen-age heroics wrapped in flashy video-arcade aesthetics.

The main character is David, a likable high-schooler with a flair for computers and a streak of mischief in his nature. Bold but irresponsible, he's not above tapping into his school's memory bank to boost his miserable grades. The plot gets going when he unwittingly dials into a military computer that's used for rehearsing World War III.

It's a lonely computer, we find out, and it just loves playing its awful ''game.'' But it seems nobody remembered to teach it to know the difference between simulating a war and really waging one. After cracking the security codes, David spends an afternoon tossing commands into his new electronic friend , thinking it's all in fun - then learns from the evening news that he almost touched off Armageddon a few hours ago.

Properly shaken, he vows to be a good boy from now on. But the computer renews contact, insisting they finish the scenario that's bubbling through its microchips. In a military ''war room,'' the government struggles to outwit the berserk machine, while David - on the run from all those angry adults - finds clues and solutions in unlikely places.

It's a clever package. With his yen for computers, David will strike a chord with every kid who's felt the lure of a Pac-Man machine. Others can identify with his bright and capable girlfriend, who has more on the ball than our hero at times and lends a romantic angle to boot.

In another direct pitch to the teen-age crowd, the authority figures are played for (sometimes vulgar) laughs, from the henpecked father to the foul-mouth general. To top it off, the computer has a voice suspiciously like E.T.'s cramped but charming tenor. There's something for everyone, especially if ''everyone'' belongs to the young age group Hollywood especially loves to woo.

For all its filmmaking savvy and laudably serious overtones, though, I have very mixed feelings about ''WarGames.''

On one hand, I'm pleased that a potentially huge hit is addressing such desperately important matters as the arms race and nuclear brinkmanship. I congratulate Badham and his screenwriters (Lawrence Lasker and Walter F. Parkes) for questioning the status quo and undermining some conventional wisdom. I particularly commend them for taking a stand or two that aren't homogenized and Hollywoodized in a fatuous attempt to please everyone; people who believe in ''winnable'' atomic wars, for example, get roundly rebutted in the final scenes.

Yet there's something much too neat, too smug about Badham's approach. The movie has about three endings during its last half hour, and each new climax ties some complicated issue into a tidy, reassuring little package that's as deceptive as it is appealing. By the grand finale, everyone in sight - from teens to generals, plus the errant computer - cozily agrees about the futility of nuclear combat and the pointlessness of atomic weaponry as a solution to anything.

If this were Hollywood's way of telling us the real world has reached these conclusions, it would be mighty good news. But it's just a fantasy, contributing nothing to the urgent debate over such matters. As fantasy, it's more relevant and I suppose more ''educational'' than the shenanigans of ''Star Wars'' and its ilk. But it's far too simplistic for comfort - and downright dangerous if it makes anyone think today's self-destructive forces will bow jovially out of sight as soon as we grown-ups loosen up a little.

''WarGames'' resolves the most important issue of our age as if it were nothing more than a spunky technical challenge. History and human nature itself are overlooked or wished away. This is no surprise, since history, psychology, human nature are just what Hollywood is weakest in these days. ''WarGames'' may look like a step forward, but it's really a child of its time. 'Blue Thunder'

A footnote about ''Blue Thunder,'' the other new Badham drama. Roy Scheider plays a helicopter-mounted cop who stumbles on political skulduggery - something about blocking progress in the inner city - and uses the bad guys' own nasty weapons to defeat them.

The movie reflects Badham's cinematic skill, but has a less personal feel than ''WarGames.'' Most of its energy goes into the action sequences, and the helicopter is the real star of the show, even figuring in the smarmy sex episodes. Yes, a bit of ''social awareness'' glimmers through the punchy screenplay. But director Badham cuts to the chase whenever the picture threatens to mean something. Films for changing times

It's the tenth anniversary of New Day Films, and that's reason for three cheers.

Founded by four independent filmmakers, New Day is a ''distribution cooperative'' specializing in works that deal with contemporary social issues. From its base in Franklin Lakes, N.J., the group now represents 29 filmmakers around the United States and has a catalog of 39 movies on subjects ranging from labor history and gender roles to creativity and the environment. New Day pictures have collectively earned five Oscar nominations and many other awards, and several have been televised on PBS.

In celebration of New Day and its members, the Museum of Modern Art will present a five-day retrospective beginning June 17. Featured will be such excellent pictures as ''Union Maids'' and ''With Babies and Banners,'' both about women's role in the American labor movement; ''The Other Half of the Sky, '' a vivid ''China memoir'' by Shirley MacLaine and Claudia Weill; ''The Last To Know,'' about alcoholism; and ''Joyce at 34,'' about parenthood. Sundry others will focus on sundry other topics.

''New cinema for changing times'' is one New Day slogan. A worthy ideal, being energetically pursued by this admirable institution.

Anti-Nazi film

As recently as a dozen years ago, West Germany's film community had done little to explore, much less analyze, the Nazi phenomenon. Since then, moves have been made in this direction, but I can't remember any picture that touches on the subject with the impact and audacity of The White Rose, a factually based drama by Michael Verhoeven that recently had its American premiere.

The title refers to the White Rose Society, a group of four university students who outwitted the Gestapo for almost a year, posting flyers - or painting graffiti, when paper was hard to come by - that attacked Hitler and his regime with forthright ferocity. The film chronicles their activities with the pace and tension of a good suspense story, slipping into coyness or confusion at times, but building impressive momentum as it moves toward its chilling conclusion.

According to TeleCulture Films, which is presenting ''The White Rose'' in the US, the film has generated a controversy in West Germany, since the law under which the society was eventually punished has never been repealed. This information lends a touch of topicality to the drama, but contemporary connections are not needed to bolster the poignancy or excitement of Verhoeven's work, which would be stirring even if its remarkable incidents were not based on the overlooked and reassuring fact that resistance raised its voice even in Hitler's miserable heyday - and under the Fuhrer's very nose.