General Igor Sergun, who as the head of the Russian military intelligence agency known as the GRU was under Western sanctions for actions in Ukraine, has died unexpectedly.

His death was announced by the Kremlin on January 4. No explanation was given, but Vladimir Putin expressed condolences to Sergun's relatives over his "sudden death."

Sergun, who had headed the GRU since 2011 and was also a deputy head of the Russian military General Staff, was 58 years old.

A week ago the general wh...