Title: Win-win scenarios
Every alien invasion raises the Pentagon's demand for his defense systems. They trust the League as much as they can trust any civilian, which is not much at all. Their mandates and survival instincts require them to stockpile enough weapons to be able to defeat anything the League has defeated, a bar that seems to be set higher every year. Money is not a problem. It never is when it comes to war. All it takes is more invasions.
Every alien invasion is a chance for Superman to die. His messiah complex seems to makes him constantly look for opportunities to sacrifice himself, in a vain attempt to earn his acceptance in a planet that will never be his. Biology and luck have saved him so far, but the odds are against him. All it takes is more invasions.
Luthor runs 24/7 an hyperspace beacon 'to foster peaceful contact.'