Did the dust up with the G7 work for or against Trump in future negotations? We have the answer:

Peter Baker / New York Times: Escalating Clash With Canada, Trump Is Isolated Before North Korea Meeting  —  

For starters,  no one has been isolated from the rest.  The events of the G7 JUST HAPPENED.  If you believe that "just happened" in the world of diplomatic disagreement,   among allies,   is the final or end result,  well,  you are just being silly.  What do you think Kim is thinking?  Right now,  he is assured of meeting with a man who means what he says   . . . . .   and that may have been the subtle point of Trump at the G7.  I believe it is a message to Kim and it was premeditated.  Look,  if you remember,  before Trump left for Canada,  it was announced that he would be leaving early.  In fact, he came late to the first meeting, as well.  He did not attend the G7 with the purpose of working out disagreement.  In fact, he did not really try.  That will come later.  The G7 sets the stage for the meeting with Kim