President Donald Trump doesn’t read, so it would be nearly impossible for him to learn from history. In 1939, Germany and Russia signed the German-Soviet Nonaggression Pact. In 1941, Germany ended the pact by launching a surprise invasion on Russian territory.
I believe the upcoming summit is a trap designed by China and North Korea, possibly with Russian prodding. The plan may be for Kim Jong Un to drag out negotiations until prior to the November 2019 elections, then sign a “non-aggression agreement” to bolster Trump’s re-election efforts. After the election? See the above paragraph.
These nations would love to see America internally divided and internationally isolated. This vacuum our president is creating will not only isolate America further but allow our former adversaries to replace us as global powers and trading partners.