Trump obviously relishes this latest installment in the reality-television series that is his presidency. The danger is that the summit will implicitly condone Putin’s brutal tactics in Ukraine, Syria, the European Union and the United States — and foster further discord within the NATO alliance, a Russian goal for nearly 70 years. Trump should consider the possibility that “Helsinki” could someday become a symbolic name for appeasement, like Munich in 1938 or Yalta in 1945.

Russia’s new diplomatic ascendancy is a Kremlin dream fulfilled. When I was in Moscow last summer, Sergey Karaganov, the head of Russia’s Council on Foreign and Defense Policy, bluntly proclaimed Russia’s hope to dissolve the “liberal international order” symbolized by NATO and the other institutions that long sustained American power. “That order we did not like, and we are doing away with it,” he said.

“Putin is about to get absolution,” fears Tom Donilon, who was a national security adviser for President Barack Obama. In Trump’s enthusiasm for reconciliation with Russia, he seems unaware that he may be seen as ratifying a long string of malign Russian goals and actions, including…