Is there a way to get rid of or disable forts?

I’m currently doing a playthrough as a social democratic Germany. I went through a relatively defensive focus tree, built a ton of forts along the French border and also recreated the Siegfried Line because I was that paranoid about being invaded. Now that I'm at war, I vastly outnumber the French and British in terms of manpower but the forts give me a huge attacking penalty. Because of them, my divisions with CAS and air superiority are currently fighting a few losing battles against half as many French/British divisions. Is there anything I can do to get rid of them, or do I just turtle it out until I can get the USA to join the war?

Sorry for not posting this in the main HOI4 sub, if it matters.

TL;DR: Built too many forts, now I basically have no capability of launching an offensive. Need to resolve this.