Who is Colonel Nikolay Grishanov from Without Remorse and what is their importance?

Colonel Nikolay Grishanov is the Soviet officer who interrogates Zacharias at Sender Green. His patience allows him to cultivate Zacharias and obtain the information needed to formulate a plan for the defense of Moscow. Grishanov wants the American captives kept alive and healthy, so he can obtain information. His plan includes moving them to Russia rather than allowing the Vietnamese to kill them.