After the collapse of the Soviet Union, we have been in a relatively stable world (9/11, Iraq, and Afghanistan notwithstanding -- none of them world war scale), but it now feels ever less so all the time.
If one has to have either a civil war or a world war (bizarre choice), a world war would actually serve to unite us, although our existing division is a weak starting place. A civil war destroys us from within, full stop.
My favorite conspiracy theory is that the CCP is sowing the division within us to drive us to civil war, whereby they win WWIII without ever firing a shot.