You're a war movie completist
Unless you're an expert on post-WWII Irish military conflicts, the actual "Siege of Jadotville" won't be familiar historical territory. The movie doesn't provide much context, so here's an intro: in September 1961, the United Nations went on the offensive against the State of Katanga, which recently seceded from the Republic of the Congo and continued to employ mercenaries to stir up violence. Katangese forces countered with an attack on a lone UN base in the mining town of Jadotville. The Irish soldiers stationed at the base were barely armed, and many had never faced wartime combat situations. The incursion lasted six days (and despite it being history, I won't spoil how the siege played out).
Director Richie Smyth takes his cues in The Siege of Jadotville from men-on-a-mission war movies like The Dirty Dozen, The Train, and Play Dirty, not to mention more modern takes like Black Hawk Down and Michael Bay's 13 Hours, while resisting the gravity of their situations. Visually, the movie's stuck in a limbo between smaller, more suffocating defend-the-castle pictures like Assault on Precinct 13 and installment territory, like a chapter of Band of Brothers without the surroundings. Still, Jadotville's existence is essential for war movie buffs; the Irish soldiers spent 40 years in disgrace after the battle of Jadotville, the victims of political cover-up and defacement. Netflix's movie is a documentation of the truth -- and should point more than a few people to the richer source material, Declan Power's Siege at Jadotville: The Irish Army’s Forgotten Battle.
You wish Masterpiece Theatre could dial it back
The Siege of Jadotville boils down the gnarled and nascent Congolese war conflict into a series of dry exposition dumps that make Downton Abbey look like Glengarry Glen Ross. The responsibility of turning historical overview into compelling drama falls on two accomplished actors: Mark Strong (The Imitation Game), as the UN bigwig who ordered the Irish troops to fend off attacks, and Danny Sapani (Penny Dreadful), playing Moise Tshombe, president of the State of Katanga. Their piercing cadences almost do the trick, even if the script can't decipher the brewing war in layman's terms.
The movie is so inundated with historical information, Smyth has little time to establish his soldiers as individuals. They banter and bicker without backstory, so by the time we see them in action, the Irish faces begin to blur. It's a testament to what a great cast can do; we don't really know or care about any of these guys, but each cast member feels lived in enough to sell it.