Do we need some nasty space aliens threatening to destroy us? I think we do.
It seems to me that most of us humans still need to have a common enemy but instead of fighting each other (and wasting all those resources on the military and weapons of destruction) wouldn't it be better that all countries focus on Alien invaders? It will unite them in a Common Goal and bring peace to this planet, and with each other.
Now I think Elon Musk (who I do admire) should launch into outer space a menacing looking alien spacecraft (not a harmless looking car) with a few lasers on board and fire those lasers at some abandoned township. Make Earth think it's being invaded instead of a country being invaded.
Simple solution. We need spacey alien threats!