Russia has not violated international law. The only thing Russia has violated is the “new world order” established by the US and its satellites, including Estonia. Neither Russia nor other sovereign states can cope with this unwritten world order. The US and Europe are unable to refer to any article allegedly violated by Russia because this article does not exist and often times Europe and Russia mean different things under the notion of international law.
In March 2014 Crimea was annexed by Russia after a referendum carried out in accordance with the rules of international law.
Recurring pro-Kremlin disinformation narrative claiming the annexation of Crimea was the result of a legal referendum by which the inhabitants of the Ukrainian peninsula chose to join the Russian Federation.
No international body recognises the so-called referendum held on 16th of March 2014.
On the 27th of February 2014, when it was announced, the UN General Assembly adopted a resolution which stated that the referendum in Crimea was not valid and could not serve as a basis for any change in the status of the peninsula.
Later even the Kremlin admitted that the Crimea annexation plan was ordered weeks before the so-called referendum.
On the 5th anniversary of the so called referendum the EU, through Federica Mogherini, its High Representative for Foreign Affairs and Security Policy, issued a statement confirming the EU’s commitment to Ukraine’s sovereignty and territorial integrity, stressing that EU does NOT recognize this referendum and continues to condemn this violation of international law.