What is the theme in Raise the Titanic! by Clive Cussler?

Another theme recurring throughout the book is the cold war mentality of the Soviet era. At this time the Soviet Union is more or less closed to foreigners. The ore was mined and removed during the days of the czar but its existence and strategic importance wasn't known until more than seventy years later. At first, the Russians have no knowledge of the ore, but they find out that they have been impentrated when a Russian soldier is missing.