No problem with developing defense for your large cities. The question is, who does MOCBA view as threat?==
Anyone who has the capabilities to attack is the threat.
The U.S. has no logical reason to attack Moscow or start a thermonuclear war. Russia is like a very bright and talented friend, but a friend with a sneaky side that we don't entirely trust. Much of that is based on history, but the defensive measure, while certainly reasonable for a sovereign nation, raises the question I asked: Who does Moscow fear, and why? What message is Moscow trying to send, and why does it feel threatened?
I grew up as a child in the 1980's having nightmares about nuclear war, about being sought by KGB agents and dogs, trying to hide around Red Square. This was especially true after the downing of Flight 007. Many American children shared similar experiences.
It would be helpful to hear the Russian side, if you care to share it.