Concerns about a natural gas emergency loom over Europe

European business executives and leaders are perspiring, but it's not the summer heat. There is concern that Russia's sabotage of the natural gas supply may trigger an economic and political crisis the following winter. Or, worst-case scenario, much earlier if Russia abruptly shuts off the gas.

Ursula von der Leyen, president of the European Commission, issued a warning on Wednesday, saying that nations and businesses must be....