What's Putin Afraid Of

Putin COULD know something he's not sharing with the rest of the world.
A former (current) KGB who won't tell the truth. What are the odds?

But all the posturing and threats issued by Putin regarding the proposed missle DEFENSE system..i.e. protection from INCOMING missles, leads one to make all sorts of suppositions regarding Putin's state of mind, his current level of knowledge regarding rogue states and their capabilities, his vision of the future of "Mother Russia" and how to make it so.

Who is Putin to make a fuss about NATO's defense?
(Putin missile remarks "unwelcome": NATO)

Why would you NOT want a defense against missles?