"I think it is obvious that NATO expansion does not have any relation with the modernisation of the Alliance itself or with ensuring security in Europe. On the contrary, it represents a serious provocation that reduces the level of mutual trust. And we have the right to ask: against whom is this expansion intended?"
(Putin 2007 in Munich, Wikipedia)
This is kind of paranoid. But there are historical reasons:
Poland/Lithuania (Władysław), Napoleon, The German Kaiser, Hitler
I am referring to the Polish Russian War from 1609 to 1618.
"The King of Poland, Sigismund III Vasa, declared war on Russia in response in 1609, aiming to gain territorial concessions and to weaken Sweden's ally. Polish forces won many early victories"
"Sigismund's son, Prince Władysław of Poland, was elected tsar of Russia by the Seven Boyars in September 1610, but Sigismund refused to allow his son to become the new tsar unless the Muscovites agreed to convert from Eastern Orthodoxy to Catholicism"
In fact, I don't have an overview of all the wars and carnage in which Russia and neighboring countries were involved.
From retaining most of the historic Russian Empire?!