BONN -- Five years ago, young West Germans were best known abroad for marching in disarmament rallies.

Today, maverick pilot Mathias Rust has joined tennis star and fellow 19-year-old Boris Becker in winning attention for the rise of West Germany's own "me generation," pollsters and commentators say.

Becker's determined play and tremendous commercial success have led him to be acclaimed as the hero of West German yuppies. Now Rust has won instant fame for another kind of individual achievement by piloting a single-propeller plane through Soviet air defenses to the walls of the Kremlin.

Theo Sommer, editor of the respected weekly Die Zeit, drew the parallel this week in a lead article. Noting that Rust had chatted "calmly" and "modestly" with astonished passers-by on Red Square after his landing, Sommer wrote that Rust was "just himself: proud of his own achievement, crazy about his thing, flying; a symbol of the young generation no less than Boris Becker."

Jochen Hansen, a senior analyst for the Allensbach polling institute, said in a telephone interview that Rust and Becker were popular here because they had "challenged the world."

Germans, sensitive about their international reputation because of Hitler's legacy, take special pride in countrymen who win international recognition, he said. "Anyone who is seen in other countries as being successful is regarded very favorably here," Hansen said.

Young West Germans, like their American counterparts, have gradually shied away from political activism and concentrated more on their careers and personal lives in recent years, according to pollsters and other analysts.

Leaders of the pacifist-ecologist Greens Party, the self-described heirs of the counterculture that sprang up in the late 1960s and early 1970s, have noted that they draw less support from West Germans under the age of 25 than among those aged 25 to 40.

The mass-circulation tabloid Bild this week described youths' top interests as "necking, earning and chic things."

But as representatives of this trend, Rust and Becker also share a vulnerability to the accusation that they are self-centered.

Becker's star has been tarnished a bit since he was hailed as a national hero two years ago for becoming the youngest player, and first German, to win the Wimbledon men's tennis championship.

Boris, as he is universally known here, has drawn criticism for transferring his residence to Monaco to avoid paying West Germany's steep taxes. Deputies of the left-of-center Social Democratic Party protested his move in parliament.

In the week since Rust made his dramatic flight, the West German government and public, presumably the older set, have had sober second thoughts about it.

After reveling in his success and chortling over the Kremlin's embarrassment, officials and commentators have expressed fears that Soviet-West German relations may suffer from what initially seemed to be a harmless prank. The mood has shifted in part because Soviet officials have suggested that Rust, now imprisoned in Moscow, could face a jail sentence of up to 10 years.

Chief government spokesman Friedhelm Ost urged reporters yesterday to treat the Rust case "seriously." The Foreign Ministry said that Rust's "foolhardy action" could have "extremely unfortunate consequences for himself and for political developments."

Rumors, originating mostly in dark hints from Soviet officials, have swirled that Rust planned the flight with the cooperation of commercial sponsors in hope of cashing in later through product endorsements. There is no evidence of such planning on Rust's part. The theory gained some publicity, however, when his family sold exclusive rights to its side of the story to the weekly magazine Stern for a price reportedly between $16,650 and $33,300.