A state-run brothel on the military base of Quemoy during the Cold War reps a scintillating microcosm of Taiwanese history in Doze Niu Chen-zer’s beautifully acted, achingly romantic “Paradise in Service.” Probing prickly themes of cross-strait politics, homesickness and sexual coming of age, Niu (“Monga,” “Love”) treats the story’s tragic underpinnings with a delicate and mildly sentimental touch, speaking volumes with gorgeously evocative period ambience. Historical interest and certain racy elements should serve the pic well on the festival circuit, but overseas commercial prospects may be limited, as no Chinese release is planned despite the backing of mainland major Huayi Media. The film opened Sept. 5 in Taiwan.

Although the $8.3 million production nearly came to a standstill when Niu was indicted on charges of allegedly smuggling his mainland lenser Cao Yu into a restricted military zone, his perseverance has paid off with his best-crafted film to date. By vividly re-creating a state-sanctioned bordello, officially called a “teahouse” and euphemistically referred to as “military paradise,” the thesp-turned-helmer has broached a taboo subject that is nonetheless an open secret in Taiwan. Far from hyping up the establishment as a hotbed of lust, the film reaches deeper into the soldiers’ psyches to depict not only sexual frustration, but also their longing for family and emotional comfort.

An introductory sequence briefly recounts a series of complex historical events and political factors that will inform every plot development and every character’s mental state throughout; indeed, grasping the drama’s many nuances may prove difficult for audiences without some knowledge of the Chinese Civil War and the cross-strait conflicts that continue to this day. Following the 1949 battle of Ku-ning-tou, a violent clash between PLA and KMT troops in the archipelago of Quemoy (more commonly known as Kinmen), generalissimo Chiang Kai-shek transformed the islands into a key military base to safeguard against further invasions by the People’s Republic of China. Skirmishes continued right up to the 1958 Taiwan Strait Crisis, when the PLA launched regular attacks on Quemoy and Taiwan’s second military base, Matsu; by the late ’60s and early ’70s, however, tensions eased, as prospects of the exiled nationalists retaking China waned.

The layered screenplay by Niu and Tseng Li-ting (who co-wrote the helmer’s previous three features) focuses intimately on a few protagonists, observing the various political sea changes through the callow eyes of a new draftee. Yet the story is more radical than it appears initially, subverting decades of propagandistic “military education” cinema implemented by the Kuomintang government to instill patriotism (typified by the “Yes, Sir” series first helmed by Cho Ao-hsin in 1987). Starting with loaded references to slogans and pamphlets that highlight the absurd, empty rhetoric of both the communist and nationalist governments, “Paradise in Service” steadily reveals the lies and self-delusions that permeate its characters’ lives, depicting the island as both an idyllic beach paradise and a prison — a backdrop ripe with allusions at once historical and contemporary.

In 1969, 19-year-old Lo Pao-tai (played by Ethan Juan), who calls himself Little Pao, arrives on Quemoy for his three-year conscription service and is assigned to the Sea Dragons, an amphibious reconnaissance battalion notorious for its severe drills. However, by a stroke of fate, he is transferred to Unit 831 to manage the teahouse, effectively becoming a glorified pimp. A different film might have contrived bawdy antics, or mocked Pao’s awkward predicament as a virgin surrounded by wanton women and horny troopers. But Niu forgoes any crowd-pleasing approach, instead affectionately extolling his protag’s vow to save himself for his sweetheart, foregrounding his innocence and alienation in the face of a system that refers to its sex workers by numbers rather than names.

The sultry Nini, or No. 7 (Wan Qian), catches Pao’s eye, but their romance is backburnered in the pic’s male-bonding-dominated first half. The central relationship is Pao’s unlikely friendship with Sgt. Maj. Chang Yun-shan (Chen Jianbin), an illiterate northerner who enlists Pao’s help with learning the Taiwanese dialect, as well as writing letters to his mother, whom he hasn’t seen since he was drafted by the KMT. As Chang’s past unfolds through Chen’s captivating narration, it gives voice to the sorrows of Taiwan’s millions of reluctant settlers, who yearned for reunion with their loved ones on the mainland. The stout war veteran’s only weakness is for Jiao, or No. 8 (Ivy Chen Yi-han), but his fantasies are doomed, as she cares only for trinkets.

Another bleak subplot follows Pao’s neighbor Chung Hua-hsing (Wang Po-chieh), who’s mercilessly hazed while stationed inside Jhaisan Tunnel. This brief interlude is made memorable by nightmarish shots of the cavernous, water-logged tunnel (lensed by Charlie Lam, who replaced Cao), contrasting with the steamy brothel rooms. Again, Niu refrains from melodrama, even when Chung’s feelings for aboriginal girl Sasa, aka No. 16 (Taiwanese-Paraguayan model J.C. Lei), takes an inevitably desperate turn.

Creating a picture of forced idleness, from the languidly voluptuous “waitresses” to the drill sergeants and their gambling brawls, the film captures the psychological fatigue of soldiers preparing for a war that may never happen, and one that they’ll likely lose in any event. Gradually, the drama shifts to the growing rapport between Pao and Nini; scenes of the pair strumming a guitar are sweetly chaste, yet tingle with repressed desire, and as bits and pieces of Nini’s past come to light, her unattainable airs melt away to reveal deep sorrow. A climactic denouement delivers the anticipated erotic sizzle before segueing into dreamy lyricism.

Himself an experienced thesp, Niu draws fine performances from a seamlessly merged Taiwanese-Chinese cast. Taiwanese heartthrob Juan (“Monga,” “The Guillotines”) may be the leading man, but it’s Chen Jianbin (known for his role in the mainland TV series “The Legend of Zhen Zhuan”) who drives the drama and provides the emotional heft as a conflicted hero/victim who’s pigheaded yet sensitive, macho yet childlike. Taiwanese cinema abounds with portraits of the uprooted, down-at-heel KMT soldier, but few have so powerfully situated him within his military environment or captured his proximity to his homeland, allowing his predicament to register all the more acutely.

With a name that literally means “protect Taiwan,” the character of Pao is freighted with symbolic meaning, but Juan fully fleshes him out, making a credible transition from naive innocence to jaded promiscuity. Mainland actress Wan completely embodies the sophistication of a Shanghainese emigre, particularly when she sings her very own mournful rendition of “River of No Return,” Marilyn Monroe’s song in Otto Preminger’s 1957 Western of the same name. As a calculating material girl belied by her angelic face, Ivy Chen Yi-han (“Ripples of Desire,” “Hear Me”) makes a minor breakthrough, limning seductiveness with a brazen, vulgar edge.

Craft contributions by Niu’s regular collaborators are aces. Huang Mei-ching’s production design is less stylized than usual but still shows his trademark love for rich tones; Lai Hsuan-wu’s costumes are unostentatious, but meticulous period attention can be seen in the hairdos and lingerie. Music by Cincin Lee makes clever use Mandarin pop songs of the era to set a nostalgic mood, their lyrics offering ironic comment on the film’s various dramatic contexts. Editing, supervised by Hou Hsiao Hsien, maintains a measured pace that suggests the passage of three years, but a little tightening around the midsection would bring a few plot strands into stronger cohesion.