The reality is that if every major country is spying on other major countries (and they are), there is no trust to violate because there is no trust to begin with.
One would imagine that every country attending a G20 summit would expect to be spied on like this, because they would be doing the same to others.
Does this somehow make the matter more acceptable on moral grounds though? I think it does not. If a government can't trust another one even when they have all sorts of contracts, policies, treaties, meetings and plans, how on earth should citizens be able to trust them?
I think the status quo should be less offensive and competitive and more trustworthy and collaborative. But then again, who would trust a liar, especially in situation where one too would lie?
One would imagine that every country attending a G20 summit would expect to be spied on like this, because they would be doing the same to others.