Many Ukrainians are worried about the new U.S. administration because it has promised a different approach to Russia—which invaded and forcibly annexed Ukraine’s Crimean peninsula in 2014 and then initiated and supported a so-called “separatist” movement to also gain control over parts of eastern Ukraine. We additionally worry that amid anti-establishment currents in Europe, coming elections across the Continent will usher in leaders who will want to make a deal with the Kremlin.

There will not be a solution over the heads...