When not making his Las Vegas heist movies, director Steven Soderbergh enjoys experimenting with film forms and genres. In "The Good German," he takes Joseph Kanon's best-selling novel of intrigue, set amid the devastation and corruption of post-World War II Berlin, then imposes on himself the style and restrictions of American studio filmmaking of that era. Thus, "German" is in black and white, shot on the backlot and in Southern California locations subbing for exotic locales with newsreel footage and rear-screen projection for exterior backgrounds, while stars George Clooney, Cate Blanchett and Tobey Maguire emote in the foreground.

The visual style -- the camera setups, editing and scene-shifting wipes -- all scream Warner Bros. circa 1945, with an undisguised nod toward that studio's greatest wartime romance, "Casablanca," even to the point of echoing the final sequence at an airport, where two lovers say goodbye for the last time, though for decidedly different reasons.

A stunt? Yes, of course, but a good one and well executed. It also allows Soderbergh and writer Paul Attanasio, in a smart, well-paced adaptation, to explore a moral complexity that never found its way into movies of that era. In "German," a 1940s studio tale of honor and survival collides with the stark realities of hard choices made by people in the face of unimaginable horror. In the old studio versions, there was always a moral high ground; in "German," that position is very hard to locate.

The demographics for this film might skew a little older than 2006 Warners might like. It calls for at least an appreciation of the old style of filmmaking. The leads will help sell the film to younger audiences, but what viewers un-familiar with "Casablanca" or "Watch on the Rhine" will make of the old-fashioned techniques is hard to say. Warners should enjoy at least modest success, and given the rising star power of Clooney, Blanchett and Maguire, possibly a breakout hit.

When war correspondent Jake Geismar (Clooney) returns to Berlin, a city where he ran the Associated Press bureau before the war, he discovers dramatic changes. It's not just street after street of bombed-out buildings and barely inhabitable rubble. It's how the laws of the jungle have seized everyone, occupier and occupied.

Russian soldiers have raped their way across Berlin. Yank soldiers, tasting for the first time the forbidden fruit of unrestricted moral boundaries, eagerly deal in the black market and commit crimes with impunity.

Jake enthusiastically accepted the New Republic's offer to cover the Allies' Potsdam Conference so he might track down a former lover, Lena Brandt (Blanchett), a married woman he hired as a stringer before the war. Tully (Maguire), a venal soldier from the Army motor pool assigned to drive him, has deep connections in the black market. Consequently, Jake finds Lena much sooner than he anticipated. Imagine his shock though to learn that Lena is a prostitute and Tully her lover-pimp. We're a long way from the reunion of Ilsa and Rick in "Casablanca," aren't we?

What drives the melodrama is an intense manhunt for Lena's husband by U.S. and Soviet authorities. Emil Brandt was a mathematician who assisted a Nazi rocket scientist whom the American authorities are eager to spirit out of Berlin to work for the U.S. rocket program. Only Emil is privy to information regarding the scientist that would be most damning were it to come out in the press or a war crimes tribunal.

Lena insists Emil is dead. Indeed, he has left no trace. Yet Lena is in constant danger, and soon so is Jake. Tully meanwhile turns up dead in the Soviet sector with 100,000 German marks in his pocket.

Things go from bad to worse as Jake struggles to help Lena. Only Lena doesn't want his help. She keeps telling him she is not the woman he once knew. She is a survivor and has all the guilt, shame and dirty secrets that come with survival. Jake fails to listen -- to his own peril.

Thus, Jake, played with sturdy, masculine thickheadedness by Clooney, becomes our point of entry into the moral morass that is 1945 Berlin. Everyone is dirty. And, in the case of Army Colonel Muller (Beau Bridges) and Congressman Breimer (Jack Thompson), cheerfully so. They see the future, the Cold War, and have their eye on the prize -- ex-Nazi scientists and who cares about their crimes. Jake remains clueless until the end. After all, there must be such a thing as a good German, right?

Clooney adds to his increasingly prestigious rogues' gallery of film portraits as the one guy in this unsavory lot trying to stay clean. Blanchett gets everything right -- the accent, her German dialogue, the weary sexuality (deliberately reminiscent of Marlene Dietrich) and the amorality her character has embraced. Maguire is wonderful as a guileless young man for whom the war has unleashed hitherto unknown desires, excitement and greed.

The seamless mix of archival footage and sets is much superior to what was possible in 1945 Hollywood. The murky shadows and slightly smudged look of the cinematography -- by Soderbergh under the pseudonym Peter Andrews -- fit the old style, as well as the theme of darkness reaching out to blot the light. The editing -- also by Soderbergh under another pseudonym -- keeps things moving right along at a let's-get-to-the-point speed that even Jack Warner would have admired.