Does the moon circle the Earth? ...or rain fall 'down'? ;^)
In all my years peripherally involved in such things, I have never seen a POTUS attend an international summit without the outcome already assured - EXCEPT BHO, who seemed to stumble from one surrender to the next.
... And then there's Canada's PM who just violated that whole normalcy. Trudeau DID deal in bad faith! He is up for re-election; I hope POTUS disem-brow-s him!
Remember the Chicago Olympic bruhaha?