The Soviets, Chinese, Brits, Yanks, and Frogs all teaming up against the Axis meant they were a part of one big nation. No other explanation, not even basic self-preservation. Nope.
The Gauls are especially a funny example since at most they were a loose tribal confederation and Caesar playing tribes against one another (some of whom requested his legions come in to stomp their rivals) is one of the most quintessential examples of “divide and conquer”.
Context: Cracker nationalist Xitter user makes erroneous claim that ethnostates were the definitive norm before big bad modernity wiped it all away. Leftist account (@Coldempanadas) responds to that and since then it’s been a cascade of bad takes showing just how simple-minded and baby-brained the understanding of world history right wingers hold is. This one in particular crowns it for me. It typically goes without saying that someone with a sober, informed worldview wouldn’t be a right winger but it should sometimes be pointed out.
On a side note, “nationalism didn’t exist before the 19th century” is a bit of an oversimplification of something that’s otherwise close to the truth. People advocating that groups with shared language, history, culture or sometimes even “blood” and familial ties should cooperate on some level did exist. But centralized nation-states before the late 18th century bourgeois revolutionary wave (and subsequent ripples reaching to the 1848 “springtime of nations”), much less before Westphalia? Especially with “nations” defined on superficial appearance or pseudo-scientific race theory and blood quantum BS aimed at justifying slavery and colonialism? Nah. If we stretch it, the closest examples would be Greek city-states like Athens, but the issue there is that those states, despite acknowledging the existence of a shared Hellenic heritage, did not think all they should constitute a single nationstate save for some “utopian” thinkers who would be thought of the same way these guys think of “globalists”.
But Rome Total war taught me that all the Gauls (even the ones in Anatolia and Spain) were all part of the same Gallic faction, and if you declare war on them, they'll all attack you and share the same economy. There's no way a video game would lie about something like that!
I'm pretty sure even in Rome (or Total War games in general before the implementation of sub-factions in Shogun 2 and Rome 2) they had the "Rebel" faction, as well as initially locked unplayables (Seleucids), to represent disunity in different countries at game start which also functions as a way to give the player a challenge and ensure not one faction would just roll over the others. There were also no mechanics where they'd magically unite into a single faction if attacked by a foreign invader.
So even someone who gets all his history from Rome: TW, where British Celts have a unit which uses severed heads as ammo or where Egypt was somehow still in the Bronze Age and pre-Ptolemaic rule in 200BC, would have a better grasp of history than your average chud.
Sid's Civilization and its consequences....