In America the night of October 30, 1938 there was DRY RUN. Orson Welles via his Mercury Theater radio program present WAR OF THE WORLDS only he didn't keep letting the audience know it was just a program.
People panicked. They were going nutjob crackpotty. They believed aliens had landed and were on the march.
No one came together. Everyone fell apart.
So I don't know if any coming together of nations would happen since there was no coming together in America...only falling apart.