Space Russia has been breathing down my neck for a while now. I'm a small, relatively inoffensive nation consisting of just four colonized worlds. We are wise in the ways of science, and have advanced construction techniques that have allowed us to build multiple habitat stations in order to upscale our production. Through various measures, our fleet cap is 724.
Space Russia has inferior technology, but somehow has a fleet cap that is so far superior to ours that their entire empire is considered OVERWHELMING. Space Russia demands our Vassalization.
We say no, rather pointedly, then offer a diplomatic insult.
They declare war next year. They demand 3/4 of our worlds, and the destruction of our frontier outposts. I demand the liberation of the worlds the just colonized on my doorstep. We scuffle for a bit, and two tactical retreats later I manage to crush their main fleet between my fleet and a Battle Fortress class defense station. A quick blitz later and I'm able to force peace, humiliating them liberating a trio of the worlds I wanted. I immediately vassalize these new worlds into my empire, which thrills them to no end.
Ten years later, I've modernized the fleet, and Space Russia is knocking again. Their empire is still fuckhuge, and their max fleet capacity is still Superior as compared to mine. However, this time their actual fleet power is... pathetic? Wait, what?
It's at this point I realize just how poorly they've expanded. For the most part, they've just been gobbling up all the empty space between the stars. Their development is shot, and will likely continue to be shot for another decade. They'd hoped to quickly crush us, but the destruction of their one doomstack dealt them a blow they couldn't recover from AND continue development on their ~30 worlds.
This time, I was the one who declared war, and I cored them like an apple. The battle was swift, and rather painfully easy. Their largest fleet this time was only a 3k, and was swept aside in the first assault. I liberated their homeworld and the four worlds in closest proximity, the well developed, highly productive, center of their kingdom.
Their empire literally splintered after the war was over, turning into six separated little blobs of poorly developed worlds, and I gained a powerful new ally from the liberated worlds.
It was a good little campaign. I'm looking forward to seeing if the ~25 worlds that remain in the control of Space Russia can pull their shit together, or if systemic unrest due to humiliation and resource shortages will fragment them further.
Stellaris