Funnily enough I watched Avengers yesterday and was reminded of the sheer stupidity of Thanos' plan.

Kill half the living beings. Great. After a traumatic event, people typically nstart banging like bunnies and you'll get a great amount of offspring and within 30 years things will be worse than before because of what you did.

Instead, bring the miracle of contraception and improve living standards for everyone and watch a miracle unfold with so much less resources required than maintaining huge armies to cause suffering