So tired of those buzzwords, used with for no particular reason.
Those countries reside on the border of Russia and logistics in operations were fairly easy and cheap. That fueled the business and money flow for may years.
Check out https://data.stat.ee/profile/country/ee/?locale=en. Russia was the second biggest trading partner, having Finland as the first. Surprisingly, if you check the trading structure of Finland, it's mostly the same Russian goods.
Russia accounts in 2B trading balance of Estonian import. This is a lot for a small country. Pretty much from the beginning of 200x the most money there were made either on raw re-export of Russian goods or processing and exporting.
If you have an idea of how to replace those 2B without rising costs tremendously, please share.