Parallel themes of honor, freedom and love run side-by-side through the World War II air war-and-amour melodrama "Dark Blue World." But the picture's stale and flimsy romance sends this otherwise stunning and profound combat story into an unrecoverable tailspin.

A fictionalized account of heroic Czechoslovakian pilots who escaped the invading Nazis and fled to England to join the Royal Air Force, the film is seen through the eyes of one such pilot who returned home after the war only to be imprisoned under a dictate from the USSR. The post-war Czech puppet government feared he and other freedom fighters might rise up against the iron fist of communism.

Part of the plot takes place in a prison hospital in 1950, where weary war hero Slama (Ondrej Vetchy) has been taken after collapsing from exhaustion while working in the stockade's factory. Here he recounts his war days to a sympathetic doctor, a former SS agent burdened with guilt about his role in Nazi atrocities.

Slama's story takes us to a contagiously romantic 1939, when he was so blind to the world from adoration for a beautiful girl that they'd make love right through Hitler's tirades on the radio. But when the Germans march into his country unopposed, Slama absconds to England with some of his best pilots, leaving his heart behind with the girl he loves.

An incredibly visceral portrayal of air battles over Britain dominates the second act of the movie, riding in the cockpits and on the wingtips of Slama and his young protege Karel (Krystof Hadek) as they engage in stunning dogfights over England and France. Director Jan Sverak ("Kolya") defies the film's small budget, making every round of ammunition, every dropped bomb and every smoking plane smashing into the sea below feel so personal and dangerous you almost want to check your back for a parachute.

But then Sverak turns on the sap as if it's coming out of a fire hose. Karel -- a nervous teenage virgin who's an ace in the air but clumsy with girls -- is shot down, stumbling (largely uninjured) in the life of a lonely, 30-ish Englishwoman. Susan (Tara Fitzgerald, "Brassed Off") is caring for war orphans while pining for her Army officer husband who is missing in action. Apparently emboldened by his brush with death, Karel comes on to her, and the instantaneous nature of their romance is so absurdly cursory that it's hard to take the rest of the movie seriously at all.

But what really comes out of left field is the sympathy-nixing love triangle that emerges soon thereafter. Susan meets Slama only once, and while there's barely a glance exchanged between them at the time, a few scenes later she's at the RAF airfield, breathless to see him behind Karel's back.

Their attraction remains unexplained and underdeveloped for the balance of the picture -- in fact, Susan practically disappears from the movie after Karel discovers her infidelity. Yet this betrayal drives the plot from that point forward, as even the war scenes become entangled in the rivalry spawned by the characters' messy love lives.

Vetchy gives a moving performance as the honorable but war-broken Slama. Although, just how honorable he might be is called into question in the last act because it's hard to get behind a guy who usurps his best friend's girl. If Slama and Susan had even a stitch of romantic chemistry, such a thing might be easier to understand. But they don't.

Further crippling "Dark Blue World" are rampant predictability and overt touches of cheap symbolism that run hip-deep in these later scenes. Then there's that incongruously upbeat ending, which plays as if Sverak is afraid of acknowledging the film's inherent sorrow.

As with this movie's wealthier cousin, "Pearl Harbor," there was a memorable, historically important war story here that could have been very well told -- if only the filmmakers had dropped the ineffectual romance and stayed on target.