I started laughing so hard at this first sentence, I couldn't read anything more. "The United Nations should assume responsibility" is just so exquisitely laughable. They can't assume responsibility for paying their own damn parking tickets; how can they protect us from an asteroid? Oh, just too funny!
Yup. It'll end up as it always does. The corrupt UN takes our money and harangues us, totally botches the job, and ultimately relies on the United States, with possible help from real scientists/engineers around the world, to finally get the job done.