I don't expect a rerun of WW2. It's hard to tell exactly how things would turn out, but the concept of having factories beyond the reach of enemy bombers is obsolete with today's aircraft. It's more likely that whoever wins the first few battles will have an immense advantage over the other, which will be reduced to guerrilla tactics.

This is all assuming it's a total war without nukes though, which is fanciful.

A conventional war between nuclear powers over a third country (Taiwan?) could maybe possibly happen by attrition, but more probably by attrition of war morale, rather than war materiel.