see if you want to war you can as said split your nation into sevral or recruit warmogrers into the game...
or you can do it abit more simple say like the good old Euro way set a retal policy that no one can acept that will either provoke a war or give you a good reason to war. just warring because you feel like it well as you can tell by the comunity isnt very popular so find a new way thats all.
the problem isnt that there is no one to war but rather the problem is that there is no reasons to war really