The Vatican has committed serious violations of civil rights and as such they should be punished. By hiding pedophile priests in their presence they are effectively interfering in the justice systems of some countries. This could be reasons for an invasion in reality if it was any other country. However, the Vatican gets special treatment from most countries. That is why the UN needs to step in.
Then they are subject to UN sanctions and these should be implemented immediately until the Vatican releases all information regarding their protection of their priestly child abusers. Allowing this institution to continue protecting, dodging and facilitating further abuse is beyond the pale and the pope should be held accountable for crimes against humanity.