It has to count as one of the strangest PR campaigns in memory: using a pile of corpses to make your case to the powers that be. That’s what Yevgeny Prigozhin, the head of the Russian mercenary group Wagner, appears to have done this week in an unusual public appeal for ammunition for his fighters in Ukraine. And in the process, he has cast a harsh light on his open feud with Russia’s military leadership on the eve of the anniversary of the full-scale invasion of Ukraine. On Wednesday, Prigozhin posted a picture on Telegram showing the bodies of several...