a way we can trust strangers en masse without sharing a flag, a belief, an ideal?

There should be. I mean we're all people aren't we? And I think there is a way to do that, because why would all these "leaders" of ours work to drive us apart if there wasn't? If I wouldn't trust you anyway, it would be pointless for a third party to push me away from you.
And secondly, we're trying. All these flags, beliefs and ideals are our desperate attempts to heal the fractures between us as a whole. So again, it must be somewhere deeper down, this need to connect and to trust.
I don't know how well this system of ours will succeed, but one can only hope and do his/her best I suppose. Very well-written, sir!