At what point (technology-wise) would the ASOIAF dragon no longer be able to dominate the tactical battlefield? The iron cannonball? The Congreve rocket? The Flak 18? Guided missiles?
It’s tough to assess anti-air technology against dragons because anti-air technology wasn’t needed until air power became a thing, and because we don’t have any data of period anti-air weapons against flying megafauna.
Certainly, dragons as field artillery are more maneuverable than our own field artillery cannons, so they would still be useful in the age of the cannonball. Young dragons could probably be taken down by firearms alone. Depending on the range of the fire breath, that might be musket volleys or you might have to wait until rifle fire to have long enough range that the dragon is simply beaten before it gets close.
We know that the older dragons get, the stronger and harder their scales become, and that hardness determines when our dragons become obsolete. I don’t know if a Congreve rocket would be very effective against a dragon; I think the dragon is too quick and maneuverable to ensure any sort of accuracy. They might fall to a Vickers gun, or perhaps we’d have to wait until the Flak 18 becomes available. Once that does, though, dragons aren’t even viable as a tactical unit, they’d be mulched by a good flak cannon.
Of course, the rider might be the biggest vulnerability, in which case a hand-cranked machine gun might be enough to shoot the rider from the saddle, and given how hard it is to get new riders, that high turnover rate for dragonriders might make them non-viable from that standpoint.
Thanks for the question, Herm.
SomethingLikeALawyer, Hand of the King