An exceptionally well-cast account of the Cuban spies vs. South Florida anti-Castro activists war of the 1990s, “Wasp Network,” comes apart in a big way almost precisely at the midway point.

The mysteries of a story about Cuban men defecting to the the U.S. and becoming pilots with the Brothers to the Rescue, a Cuban emigre air force with the proclaimed mission of guiding the Coast Guard to rafts of “boat people” fleeing Castro’s Cuba for Florida, disappear and our big questions are answered, an hour in to a two hour movie.

Yes, Rene Gonzalez (Edgar Ramirez), a doting dad and loving husband who abruptly and cold-bloodedly abandons them (Penelope Cruz is his wife Olga) to take his skydiving jump plane across the Florida Strait to Los Estados Unidos, is a Cuban spy.

And yes, the more mercenary Juan Pablo Roque (Wagner Mouro), who snorkeled his way from a Cuban beach into Guantanamo Bay, where the United States maintains a base on the island, defects and then marries the gorgeous divorcee played by Ana de Armas (“Knives Out!”), is also an agent for Castro.

Their activities — saving refugees, but also flirting with involvement in drug smuggling, which both reject — are laid-out as the boss of their “Wasp Network” of spies (Gael Garcia Bernal) takes charge.

It’s as if French director Olivier Assayas realized chatty, relationship-centric French films (“Non-Fiction,” “The Clouds of Sils Maria,” “Personal Shopper”) are his thing and either lost his nerve or his patience with this involving if not exactly “thrilling” docu-drama/spy thriller.

And here I was, all set to praise Netflix for gathering this cast, telling a fascinating and important story and making amends to Ramirez for the atrocity that was his last Netflix outing, “The Last Days of American Crime.”

It’s not as if a story about the Castro provocations and underworld activities of South Florida’s most fanatical anti-Castro Cuban Americans isn’t worth telling. But Assayas is less interested in their murky politics and financing and more fascinated by the “heroic” Cuban efforts to battle American sanctions and the blind-eye the U.S. turned on the “terrorists” it allowed to do what they want from the safety of airfields in S. Florida.

In a movie about fanatics, he chose the less interesting ones — dogmatic, Fidel-worshiping communists — to build his movie on.

Ramirez makes a marvelously myopic man with a mission. Not even his wife knows what he’s done this for. No, she isn’t telling their daughter the truth about what happened to Daddy.

“I don’t want her to learn her father is a traitor,” she hisses on the phone (in Spanish, with English subtitles).

His contacts with the Cuban American National Foundation have him flying, without warning, to Honduras for a touch-and-go drug shipment, which he will not repeat.

“I didn’t defect to run drugs,” he declares to his contact with this “liberate Cuba” organization that runs Brothers to the Rescue, and is financed with drug money. “I’m working for the liberation of Cuba!”

Roque is confronted about the secrets he is keeping from his suspicious bride, and his spending habits.

“I didn’t flee Cuba to come to Miami to be a loser!”

That dichotomy, man of principles vs mercenary professional spy, isn’t enough to hang “Wasp Network” (what they Cubans named their spy ring) on.

Bernal, when he shows up, is limited to being Mr. Exposition, explaining things to his spies, other characters and the audience.

Cruz’s character is set up to be more of a central figure than she winds up playing, and de Armas is reduced to beautiful, testy set dressing.

The entire second half of the picture feels perfunctory, with FBI intrigues, Cuban secret police and Cuban Air Force self-righteousness and Castro and Clinton public statements about what’s been going on.

It’s not as if I’m not open to a movie relating how the ineffective American embargo crippled the island and forever soured relations, how that made Cubans there as fanatical as many first generation Cuban emigres over here.

The excesses of that South Florida mob have been well-documented, if not discussed here.

The violence that results from the activities shown in “Wasp Network” is frittered away, with little suspense, tension or trauma. If this Cuban “infiltration,” which the film essentially celebrates, was so successful, and if the FBI was as tuned-in to what was coming, how did either side let the third act bloodshed happen?

Ramirez and Bernal crackle in their few scenes together, spies who effortlessly switch to Cuba’s preferred “second language” (Russian) to avoid giving away their secrets, as if two Cubans speaking RUSSIAN wouldn’t set off alarm bells in South Florida.

There’s too much to “Wasp Network,” much of it good, to dismiss it out of hand. But it only takes an hour of this two hour-plus movie for us to figure out Assayas wasn’t the right writer-director to pull it off.

MPAA Rating: TV-MA, violence, drug content, sex

Cast: Edgar Ramirez, Penelope Cruz, Ana de Armas, Gael Garcia Bernal, Tony Plana and Wagner Moura

Credits: Directed by Olivier Assayas script by Olivier Assayas, based on the Fernando Morais book.

Running time: 2:03