The first time I allayed to test Ukraine, I died early, but USA capped Cuba and Japan took dprk. Soon after, china declared against japan. And got conquered, then i lost to poland when i tried to invade.
settings were high volatility, very easy diplo, and GC map. In my current game I accidentally started with easy diplo instead, resulting in no wars at all. When I realized this I changed settings, but still no wars. So I loaded into multiplayer to recreate the events. To randomize things a bit, I also use a coin flip, like with the jap invasion... I flipped a coin between Japan and ROK to determine the invader, because Korea usually does it in my other games. Same thing before I go to war with someone mobilizing at my border... I flip to see if they launch a preemptive strike before I can finish setting up...makes war harder sometimes.I did that for the Romania war.
The rest is just storytelling.