I have always felt sanctions work effectively when rich people are severely affected by them. Russia is a case in point. An article from Bloomberg quoted the following facts.
Amid market turmoil provoked by the Ukraine conflict, the 19 richest Russians lost $14.5 billion since the start of the year, compared to an increase in wealth of $56.5 billion for the richest 64 Americans, according to the Bloomberg Billionaires Index.
Whilst this may not deter someone like Putin as quickly as you would expect, it’s at least affecting those in his inner circles and soon it will start to affect him.
