RUSSIA: AuRevoir, Potemkin?

When the British first began searching for mercenary forces to put down the American Rebellion, they turned not to the German princelings of Hesse and Brunswick but to mighty Empress Catherine II of Russia. They even made a formal offer of £1 per man for 20,000 of her infantrymen, to set sail this spring. Catherine rejected the plan as "undignified." Besides, said she, "I am just beginning to enjoy peace."

She was hardly exaggerating. Only four years have passed since she joined the Prussians and Austrians in...