Not really trying to make any real point here, just tap-dancing on the scales of debate.
Isn't Thordan literally the guy accepting disastrous power from an external source? And then when he turns it back on them, he says:
Which kind of mirrors:Originally Posted by Thordan
Derplander later joined them, but he didn't ever say we misunderstood their methods, just that the ends do justify the means. The original world must needs be restored, or whatever.Originally Posted by Derplander
And yet imho this is still true. The Ascians see someone who's about to start running and (if so required) strap a rocket to their back, causing Rocket Man's enemies to become desperate (hopefully desperate enough to summon primals). If Rocket Man's war doesn't start a Calamity, or it looks like he might win, no problem; just give Rocket Man's enemies more power and see where that goes.
Without Ascian involvement, mankind would still have ambition. Wars would be waged. People would die. Empires would rise and fall. But (as far as we've been led to believe) they would never be waging that war with so much power that it would cause a Calamity. The War of the Magi is the only hint we have that it might (so far), and Mhach spent the entire time harnessing the void, same as Allag. Ascian involvement proven? Gods no. Implied? A bit. Especially when 1.0 said that the Sixth Umbral Era had "a cabal of immortal mages" at its center.
A nitpick, Crystal Tower led to generations of peace. Dalamud was created at the end of the era, right before the Calamity. And, imho, nothing so much "backfired" as much as "was a chaotic clusterf[kupo]k by design". Everything Allag and the Meracydians did (sometimes with Ascian assistance) led directly to a Rejoining.
Because of the Crystal Tower, the Empire was on the decline - they were desperate to avoid collapse. Suddenly, Allag develops crazy advanced technology (maybe Ascian involvement, maybe not), bringing Xande back from the dead around the same time Azys Lla goes into production. Xande immediately tackles his one regret, having failed to take Meracydia. Faced with total invasion, the Meracydian tribes are desperate; primals (Warring Gods) are summoned (Ascian involvement). At the same time, the citizens of Allag rise up in revolt against Xande's tyranny. Xande is stretched too thin. Desperate, he makes a pact with the Cloud of Darkness and harnesses the power of the void, cutting down the resistance. The Imperial Army slays Bahamut and tears through the Meracydian brood(s). Tiamat's remaining forces are on the brink of annihilation; desperate for salvation and revenge, they summon Bahamut as a primal shade (Ascian involvement). The powers of Darkness can't be sustained - the Crystal Tower is running short of energy.
Suddenly, the Aetherochemical Research Facility develops the means to trap the Triad and eventually Bahamut (Ascian involvement according to Tiamat), hurling him into the sky encased in Dalamud. There wasn't much time between then (probably months, perhaps years, probably not generations) and the appearance of a small band of brave warriors that become beacons of hope and lead the charge against Xande and the Darkness. That's when Xande decides "Screw this, the Cloud can have everything." and discharges Dalamud's entire energy supply in an attempt to throw open the voidgate, ushering in a massive earth-aspected Calamity.
Would Allag have waged war without Ascian intervention? Oh, hells, yeah. They'd have slaughtered thousands. Hundreds of. Millions. But how many layers of Ascian involvement are between "Allag uses advanced aetherophysics and machina in an attempt to build a global empire" and "Xande discharges incalculable amounts of energy directly into the planet's surface from a solar-powered lunar-oribtal weapons platform sustained by a superprimal energy transistor"?
There's probably room for debate.