Your country may be perfectly at peace with the US now, but there is no way to guarantee that peace unless we have people to continually watch for potential threats. Even that is, in itself, no guarantee, but it's better than nothing.
Maybe someday, mankind will be able to share universal goodwill and peace, but until that time, trust, but verify, at a minimum.
For all of the talk about "all men created equal" and "do to others as you would have them do to you", fundamentally Americans are brought up to believe they are different or "exceptional" to other humans. This belief let's them distort reality so that spying on innocent foreigners is ok but spying on innocent Americans is an abomination. Hypocrisy.
Timothy McVeigh and others prove that the domestic threat to the US is as serious as the foreign.
/s