It's annoying democratic nations can't declare war!!!!!!
That's not true, you only have to be more ressourceful to accomplish it. You can increase another nation's belligerence with spies and move the sliders towards maximum hawk lobby and interventionism so that 1 belligerence is sufficient for a declaration of war.
Just think of this as an added roleplaying hurdle - you have to give your countrymen a very good reason to fight if you are the one starting the war.