The Wagner Group, a shadowy Russian private company working hand-in-glove with the Russian government, has recently emerged as a major player in the thriving mercenary business.  It commenced operations by providing the military muscle for pro-Russian separatists in eastern Ukraine during 2014.  Since then, its thousands of armed men have brought widespread death, torture, and rape to Syria, the Central African Republic, Libya, Mali,  Mozambique, and Sudan.