Dorchacht very likely would have, before the revolution. They kept a standing army, and I've no doubt they would've used the Monsters as shock troopers and expendable resources to clear through to Aefenglom. In truth, it wouldn't have been very difficult, either, for them to fell the city, if they got even a nominal fighting force across either Wilde or sea.

[At the time, Maria wasn't even sure if she was going to bother defending Aefenglom if they got themselves into that situation. Nowadays... well, she'd rather not see the city fall. She could live in Dorchacht if she had to, but she likes her home and garden in Aefenglom proper.]

They stand to gain more than we do, either way. Without sunlight, their choices in food is... limited. [It has been like five minutes and she's already sick of algae and worm meat.]