We're all doomed!!! (seriously though, I loved playing C&C, stopped after Tiberian Sun and RA2)
Anyway, if all or some of his work survived, the U.S. military was crazy enough to see him demonstrate his death ray superweapon. Maybe they come up with an 'improved' version of it? Whether or not it kills the atomic bomb and nuclear research in general is debatable, but if the U.S. military does succeed in building a death ray (and that's a big
IF), its probably not going to be used save for homeland defense.
Also, his earthquake-making machine would wreak havoc in the West Coast, Japan (assuming we kill butterflies and have WWII as OTL), and any other unstable tectonic regions.