Broadly speaking, China’s World War II began before anybody else’s, and ended with the conclusion of the long off-and-on Chinese Civil War that preceded it and postdated it.

Any trip down the rabbit hole of the various Sino-Japanese wars, considered a sideshow of the global conflagration by Westerners, is going to be messy and feature various alliances, “war lords” as war leaders, collaborators and the Japanese trying to swallow a divided nation many times their size through conquest, treachery and outright barbarism.

As China’s military record in the field was nothing to wave a big red flag over, combat movies from a Chinese perspective are more propagandistic fantasies than anything truly historic — even the ones that don’t feature Bruce Willis. Safer ground for filmmakers seems to be tales of espionage, intrigue and resistance.

“Cliff Walkers” and “The Message” went that route, and that’s where writer-director Er Cheng takes his moody, murky thriller “Hidden Blade.”

It tells the story of the war years through the eyes of spies who work for the the nationalist Kuomintang of Chiang Kai-shek, the collaborationist “We just want peace” government of “President” Wang Jingwei and the communists, whom everyone else — occupiers and resisters — figures are the “real” threat.

There’s an “it’s never too late to change sides” ethos among most, and that even goes for the cynical Shanghai-based Japanese intelligence officer (Hiroyuki Mori) who’d rather be in the first conquered corner of China, Manchuria, “the fortress” against Soviet invasion, or so the Japanese believed at the time.

It’s interesting that Cheng, who did the gangland WWII tale “The Wasted Times,” takes pains to show the Japanese point of view, the “How do you win a war without a goal?” realization of some who figure their island empire has bitten off more than it can chew in its “land war in Asia” blunder.

But “Hidden Blade” has many characters and points of view, from sketched-in “honey trap” female spies ( Xun Zhou, Jingyi Zhang, Shuying Jiang) to government functionaries, Japanese troops in the field committing atrocities and a bomber co-pilot who keeps his dog, “Roosevelt,” in the cockpit with him on missions.

Cheng’s narrative flips back and forth in time, from early war interrogations to late conflict walks along a river delta littered with the corpses of Japanese invaders. So it’s a little hard to follow thanks to his needlessly untidy storytelling.

It still immerses us in uncertain, nerve-wracking times as we follow well-dressed and well-fed city spies, officers and officials down the corrupt, back-stabbing road towards communism’s triumph. And it features just enough action, including a couple of the most savage brawls in recent screen history, to deserve its “war movie” label.

Hong Kong acting legend Tony Leung (“In the Mood for Love,” “Red Cliff,” “Chungking Express”) is Mr. He, a smiling, silky-smooth debriefer/interrogator who surfs the shifting currents of China’s struggle but sees the safest ground in the employ of the collaborationist Wang regime.

But even the ruthless Mr. He has his blind spot. Yes, it involves a woman assassin (Xun Zhou) working for the communists.

Sino-Korean boy-bandmate and TV actor Yibo Wang gives a breakout performance as the brooding Mr. Ye, an agent so pretty that our first and second impressions are that he’s romantically involved with his partner and constant dinner companion Mr. Tang (Chengpeng Dong). But Ye also has a woman he is trying to save from this slaughter.

The women are this spy war’s philosophers, intoning truisms that hold for any civil war or violent political divide.

“It’s easy to forgive an enemy, impossible to forgive a friend.”

Real history skips back and forth underneath this ebbing and flowing narrative, with the Japanese in China certain that they’re about to join Germany in invading the U.S.S.R. (Their dictatorship was most terrified of a war with Russia, throwing Toyota-tanks against real armor. But Stalin was also obsessed with a Japanese stab in the back.). There are scenes that capture the round-up of foreigners in Shanghai depicted in “Empire of the Sun,” mentions of The Rape of Nanking, an anti-spy raid that goes wrong and an everyday atrocity in the countryside, summary executions and a mass “punishment” of locals accused of fouling a well.

They are buried alive as a concrete foundation is poured for a new grain elevator.

As you can gather, there’s a lot to get in and a lot to take in, and Cheng’s storytelling doesn’t make absorbing it any easier. You’d think he watched “Inglorious Bastards” a few too many times, the way he stages every interrogation as a long string of soliloquies, characters giving monologues to each other that pass for conversation.

But Leung is terrific, and Wang holds his own and dazzles in a couple of epic fights. The women characters are secondary, but there’s room to play around with their degrees of fanaticism. The Japanese officer Watanabe (Mori) is almost sympathetic thanks his delusions and disillusionment. Watch how he sees a raid go wrong and gets out of his car and pulls out his samurai sword and to salvage it. Listen to how he takes the news that a Japanese prince has been assassinated on duty in China.

“I guess I’ll have to disembowel myself to apologize.”

I found the whole “Hidden Blade” rather less satisfying than its individual component parts. The many characters, myriad plot points and points of view and added complications with the narrative timeline clutter things up.

But scene after immaculately-realized, quietly-menacing scene pays off. The violence is shocking even when it’s not sudden and the messaging is less heavy-handed than typical Chinese fare set during WWII. Whatever went wrong for China on the battlefield, the secretive men and women hiding their politics and taking the measure of all their many enemies were a real success story, even if they’d never recognize the oligarchical, class-conscious “People’s Republic” of today.

Rating: unrated, graphic violence

Cast: Tony Leung, Yibo Wang, Xun Zhou, Jingyi Zhang, Shuying Jiang and Hiroyuki Mori.

Credits: Scripted and directed by Er Cheng. A Well Go USA release.

Running time: 2:10