With the cold war seeming like ancient history and movies still reeling to define a post-9/11 world, the espionage thriller, once such a vital and sturdy-looking artifact, can no longer avoid an overhaul. Even the most estimable recent efforts, the very enjoyable adaptations of two of Robert Ludlum's Bourne novels, seem suspiciously old-fashioned now-less big-screen expressions of the violence and social uncertainty in our current era than escape hatches to the relative comforts of the previous one.

Lior Ashkenazi at the airport.

Walk on Water, the latest feature from New York-born Israeli director Eytan Fox, offers an essential forward step for the genre. Fox has worked steadily for years, but his international breakthrough was Yossi & Jagger, a nervy gay love story set in the Israeli army (just to give you an idea of his credentials for provocation). Provocateurs may come cheap in movies now; the rarer breeds, the ones worth watching, also have humility and something to say. Walk on Water combines sensitivity, moral seriousness and instinctively cinematic storytelling in unprecedented ways. What's best, it feels very much like a work in the present tense. In fact, Fox is so eager to comment on today's world that he might be biting off more than he can chew. Walk on Water contains enough hot-button moral issues to have been featured prominently at Jewish, gay, and international film festivals. It is almost exhaustingly topical.

Eyal, a pitiless Mossad agent played to perfection by the Israeli heartthrob Lior Ashkenazi, has orders to track down and finish off an ageing Nazi war criminal. He must get to his target through the man's grandchildren who are now young adults. So, when Axel (Knut Berger) visits his estranged sister Pia (Carolina Peters) in Tel Aviv, Eyal poses as a tour guide to spy on them. Before he can get a fix on their grandfather, however, the hardcore assassin is unsettled to discover that these two open souls have managed to befriend him, and that Axel is gay.

Director Fox wastes no time establishing how deeply Eyal is entrenched in militant Israeli machismo. In a lethal marvel of narrative economy, we see him kill someone (presumably a Palestinian terrorist) in broad daylight and in full view of the man's wife and little boy, even before the opening credits. Then, after brief and hearty congratulations from agency cronies, we discover, as Eyal does, his wife's suicide. She has left a note, but all we're allowed to see is his unnaturally stoic, tearless response. Yet, here we are, rooting for the guy because it feels like the director has asked us to, and there is no question that the director trusts our intelligence.

Moreover, Fox obviously has plans; Walk on Water is a movie that knows its intentions, that moves, and we take it on faith that it will deliver its protagonist and us from the realm of brutality where it begins. In compelling ways, the movie obeys spy-thriller conventions. It is inherently plotty. It covers a broad geographical range-from Istanbul, where the opening scene occurs, through Israel, including a scene of arresting imagery at the Sea of Galillee, to, inevitably, Berlin, where the urban chill feels like a cloak of impending doom. The film has a great star in Ashkenazi-at once menacing and empathetic, seemingly carved out of the elements of his story. As Stanley Kauffmann has observed, "In temperament, in essence, he is Humphrey Bogart in Israel today. This is to imply not imitation but innate qualities and the tending of them."

If the film isn't 100 percent sure-footed, I don't count that against it; otherwise, it would seem too much like a miracle, and we must learn not to depend on those.

But Walk on Water is not merely an update of the conventional thriller. The movie is self-conscious about shifting paradigms. It traffics in generational tension and surprises us with emotional complications and reversals of expectation. When Eyal complains to his boss Menachem (Gidon Shemer) about the assignment to kill the old Nazi, "No one gives a damn anymore. He'll be dead soon enough," the boss squarely replies, "I want to get him before God does." Pia mentions how people ask her if she has any Nazis in the family, and when she answers yes, they pity her. Axel hooks up with a Palestinian Arab in a nightclub, inflaming not only Eyal's ingrained bigotry but also the peculiarly possessive affection he has developed for Axel in spite of himself. Later, Eyal throttles a gay basher in the metro and is shocked when Axel, ostensibly a bourgeois "peacenik," says, "It's too bad you didn't kill him ... Those people were shit." Indeed, one of the movie's richest intrigues lies in the way Axel and Eyal rub off on each other.

The director and the screenwriter (Gal Uchovsky) haven't abstained from a stance on ethical justice, but they are careful not to let any character stand for any single, neatly packaged political attitude; and all the actors bloom with that freedom. Nor are they above a kind of sentimental cinematic lyricism-Eyal's inability to cry turns out to be a medical condition, remedied with eye drops; his marksmanship, meanwhile, is inversely proportional to his emotional availability-but these touches are delivered so succinctly that they seem indispensable. And they remind us, pleasurably, that we're at the movies.

Walk on Water's jarring epilogue, which sounds a hopeful note, probably felt necessary to Fox and Uchovsky, but it will seem bogus to anyone who takes the movie as seriously as it deserves to be taken. It is still a political thriller with a story bracketed by political killings. But in the din of shrill commentary on the modern world that is available in movies now, Walk on Water's non-triumphalist tone seems nourishing and affirmative. Fox should be encouraged for his instinct to open some tough questions and to leave them open. If the film isn't 100 percent sure-footed, I don't count that against it; otherwise, it would seem too much like a miracle, and we must learn not to depend on those.

Maisonneuve contributing editor Jonathan Kiefer writes about the arts for various publications in San Francisco, where he lives. One of his cats is named after Preston Sturges. Film Flâneur appears every second Friday.