Earlier quoted context omitted.
Perhaps, as with the US you retain the honorific title 'President' even after leaving office.
Actually, you don't. Former Presidents are just addressed as "Mr Obama". http://emilypost.com/advice/addressing-a-former-president-of...
https://www.whitehouse.gov/1600/presidents/williamjclinton
Where I live, Finland, a "President" is the official title for former presidents (there are now three alive) so I should actually address them as such. The current one is formally referred to as "President of the Republic". I can't really check how this is with Russia.