Nurse Zhivago meets Gilda Hari in a love triangle and sweeping war story, "Head in the Clouds."

	'Head in the Clouds' Rating: R for sexual themes, scenes and nudity. Starring: Charlize Theron, Stuart Townsend, Penelope Cruz. Director: John Duigan.

The male hypotenuse is Guy (Stuart Townsend), an earnest Cambridge scholarship student who is low-born but not low-brow. Gilda (Charlize Theron), on the other hand, is a high-born hedonist -- the product of an aristocratic French father and dysfunctional American mom. One dark and stormy night, she stumbles into Guy's room and life, on the lam from one of flings galore. Can love with Guy be far behind?

No, but neither can separation. Three years later, they are reunited in Paris, where Gilda has become a darling of the fashion-photography salon set. These days, she's living with Mia (Penelope Cruz), a beautiful Spanish nurse/model. They're more than just friends. Our hero -- a lucky Guy, indeed -- becomes their roommate and they become a happy, sexy threesome.

But it's 1936. Soon enough, their revels and relationship are clouded by the rise of fascism, in general -- the Spanish Civil War in particular. Mia longs to go home and do her part. Guy is ready to fight Franco, too. They care deeply. Gilda couldn't care less:

"There'll always be wars," she shrugs -- pouring another whisky.

Mia, with Guy in tow, returns to Spain. Guy's letters to Gilda are returned to sender. The bloody defeat of the Spanish Republicans leads directly to Hitler and the real thing -- World War II, for which doomed Spain was just a tragic rehearsal.

Huge (and inept) jump to D-Day eve, 1944: Guy comes back to Paris, serving British intelligence and the French Underground, only to find an ugly truth instead of a romantic reunion: Gilda -- thinking always and only of herself -- has taken up with a Nazi officer (Thomas Kreutschmann).

The lover becomes the enemy.

Fine acting characterizes the picture all around. Theron is powerfully whimsical, and Townsend (so terrific in "Simon Magus" and "About Adam") is gently winsome from start to finish. Cruz ("All About My Mother"), looking eerily like Maria Callas, provides the soulful glue between them. British stage actor Steven Berkhoff has a particularly nice turn as Gilda's haughty right-wing father during a fabulously stiff, baronial dinner-table scene.

For that matter, these "Clouds" contain many effective moments and evocative images, thanks in no small measure to the lush cinematography of Paul Sarossy. Trouble is, the whole doesn't quite equal the parts. Writer-director John Duigan's ambitious goal is a wartime romance of "Casablanca" or "English Patient" proportions. But his script lacks the coherence -- and his direction and editing lack the brilliance -- of those epic paradigms. Low-budget battle scenes and a fast-forced climax don't help.

Even so, "Head in the Clouds" is visually and emotionally engrossing, a noble one. Duigan's fascination with the middle period -- that devolution of the Roaring '20s into the Rotten '30s -- is well placed, if less well realized, as the tragic run-up to a world at war.