@potus badly mishandled DPRK policy. USA weaker as result. 3 changes made summit possible:
1) President Moon elected President ROK, reaching out to DPRK;
2) KJU consolidated political and military power;
3) Max pressure by UN/Trump
Bolton knew (even if Trump did not) what that meant.
And I should have added, “...unless DPRK plays it very smart and comes back with a gushing letter of their own flattering @potus for his bravery, in which case all bets are off...”