Short answers, pulled from the story.
The formal establishment of the Eurasian Economic Union began with a series of treaties signed between 2014 and 2015. Leaders of Belarus, Kazakhstan, and Russia signed the Treaty on the Eurasian Economic Union in Astana on the 29th of May 2014. The treaty came into force on the 1st of January 2015, creating a legal framework for supranational governance.
Armenia joined by signing its accession treaty on the 9th of October 2014, which took effect on the 2nd of January 2015. Kyrgyzstan followed suit, signing its agreement on the 23rd of December 2014 and becoming a member on the 6th of August 2015. These expansions brought the total population of the union to approximately 183 million people alongside the original members of Belarus, Kazakhstan, and Russia.
The Supreme Eurasian Economic Council serves as the supreme body composed of heads of state from all member countries. Executive functions fall to the Eurasian Economic Commission, headquartered in Moscow. A judicial body known as the Court of the Eurasian Economic Union replaced the previous court system in 2015 and is located in Minsk.
In 2012, members produced approximately 20.7% of the world's natural gas and 14.6% of oil and gas condensate. Belarus relies heavily on access to Russian hydrocarbons importing crude oil and natural gas at below-market prices while paying $173 per thousand cubic meters of gas compared to $250 charged to Armenia or $430 to Ukraine.
Tajikistan was formally invited to join and has expressed interest in acceding to the bloc with negotiations currently underway to finalize terms. Iran emerged as another key partner designated as an observer member during a meeting in St. Petersburg on the 26th of December 2024. The union granted Moldova observer status in April 2017 though it ceased attending meetings after Russia’s invasion of Ukraine began in February 2022.