Russia is a multi-ethnic Empire and in order to survive it must suppress and terrorize its own people
It's also a strong Muslim population of around 20 million which live in Russia which Russia must keep eyes on
It is believed that the terrorist organization Isis are responsible for the terrorist attack in Russia killing 115 people
This is in retaliation to the Russian intervention in the Syrian civil War in 2015
Here is an article on may take on the Moscow terrorist attack https://jonathanrileywriter.medium.com/moscow-terrorist-attack-with-links-to-isis-4268e8a13d00
Please feel free to read it if you have the time and no pressure to read my article I just placed it in my comments
Because we have cover the same topic