Basically, which of the factions of the Fire Emblem series can demolish, or at least beat modern militaries in a war.
Although Fire Emblem factions are shown to be using medieval weaponry, surely magic would help them stand a chance against the technological might of Earth's militaries.
The goal isn't necessarily to conquer or destroy modern nations. The only condition that is absolutely necessary is to force the modern nations and their militaries to surrender.
Can any of the Fire Emblem factions in all Fire Emblem games do this?