As a result of collecting various information, it is clear that the reason why Russia invaded Ukraine was to restore territory to the Soviet Union a long time ago.
The reason Ukraine is currently forced to be invaded is that it has become vulnerable to the appointment of comedian President Zelensky, who became president after four months, and a large number of close aides who were close to them in important positions.
Taking this opportunity, Russia invaded.

I think that without security and defense at all times, any country will inevitably be invaded.