To address global security issues, Donald Trump has long espoused a worldview that favors big-power relations over U.S. leadership of values-based alliances.

Perhaps no relationship captures that preference for dealing with big powers, and in particular authoritarian ones, so clearly as President Trump’s decadelong affinity for Russian President Vladimir Putin. And no conflict has crystallized this attraction to the world’s stronger nations over their weaker victims of aggression as has Russia’s war in Ukraine.

This week, the Trump-Putin relationship and its implications for world affairs have been on full display.

White House envoy Steve Witkoff met with Mr. Putin in Saint Petersburg on Wednesday, presenting a proposal for renewed three-way peace talks on the Ukraine war between Russia, Ukraine, and the United States. Later, the Kremlin said it accepted the proposal in principle, though only at a lower, technical level.

For his part, Mr.…