Honor Harrington -- For the Honor of the Treecats, Destroy Everything!!!

[The Glyphstone]

It's been a very long time, so you're probably right. I just remember the assorted humanoids wars having big ships, then when the Bug Swarm invaded they built Even Bigger Ships, then after the Bug Swarm war the refugees from another galaxy showed up in EVEN BIGGER SHIPS. It just felt like plot-driven escalation more than an arms race, though again it has been a very long time since I read through that series.