But it wasn't just our allies. Snowden revealed details about NSA spying on Syria during their civil war. That is the exact type of thing that our spy agencies should be doing. If you object to that, you object to the entire nature of intelligence gathering. That is a perfectly acceptable stance to have, but it obviously isn't one that is held by the US's or most nation's government and therefore they wouldn't want to tacitly endorse it by issuing a pardon.