THE passage of a cargo ship from Ukraine to Turkey last week vindicated Kyiv’s gamble that Russia would not act on threats to attack commercial shipping in the Black Sea. But the successful gambit leaves a bigger question for Ukraine: will any other commercial vessels follow the Joseph Schulte and dare to call Russia’s bluff? The German/Chinese-owned cargo ship was the first vessel to make the journey out of Ukrainian waters since July, when Russia warned it would consider any civilian vessel...