In a recent interview with GQ, Elon Musk expressed concern about his vision for colonizing Mars being foiled by another World War.

Elon Musk is very passionate about a number of projects, and among them is a plan to colonize Mars. 
However, in a recent interview with GQ, he expressed concern about his Martian vision being foiled by especially aggressive Earthlings. 
Musk commented, “I don't think we can discount the possibility of a third World War…and if that does occur it could be far worse than anything that's happened before. Let's say nuclear weapons are used. I mean, there could be a v