What am I supposed to do with being at war with the dervish state at the start of the game?

I can't naval invade because they stack units on their ports and beaches. I have watched the ai spent literal decades trying to do so, in my games where the uk doesn't get involved in ww1.

I can't bomb them into dust because there is not enough air cover or close enough airfields.

The stability penalties cripple you within a few years, if you don't end the war sooner than later.

Going fascist so I can attack through ethopia has its own problems as well. 90% of your puppets rebel and abandon you. The terrain is unforgiving making it another long war, and again you are at 0 stability before you can even declare war.

I honestly don't see how the uk can manage in the ww1 scenario unless they join the allies and attack the dervish state through italy and frances provinces.

And that seems like a flaw to me with all the different historical paths you can take.