The U.S. war on Iran set up Russia’s economy for a major rescue after oil prices soared after the closure of the Strait of Hormuz. But if President Vladimir Putin was expecting a huge windfall, that view may literally be going up in smoke. With one-fifth of the world’s oil supplies cut off, Russian oil suddenly became much more valuable. After trading at a steep discount to Brent crude, Urals oil nearly reached parity with the global benchmark. The U.S. also temporarily lifted sanctions on Russian crude, despite warnings that the move would provide a vital influx of revenue to...