Lieutenant General Igor Kirillov, the head of Russia’s Radiological, Chemical, and Biological Defense Forces, tragically died in an explosion on Tuesday morning. The blast, which also took the life of his aide, happened near a residential building in Moscow’s southeast. Investigators believe the explosion was caused by a bomb hidden in a scooter.

Kirillov was a high-ranking military officer who had been involved in some of Russia’s most sensitive and controversial operations. From 2014 t...