Russia voluntarily let Ukraine secede from the USSR under certain conditions, which they have not kept
Please identify the specific treaty/protocol you are referring to, and which clauses you believe Ukraine has violated.
Clearly under the same principle that Russian majority that lives in eastern part of Ukraine
There was no such majority before Russia's invasion of 2014 (as explained in the other comment). It seems you may be confused by the fact that there were higher numbers voting for pro-Russia parties, or who spoke Russian/Surgyk. But that's not the same as being, or identifying as "Russian" -- any more the fact that English is the dominant language in Ireland means everyone living there must be "English".
This is one of the most important things to understand about Ukraine.
Please identify the specific treaty/protocol you are referring to, and which clauses you believe Ukraine has violated.
Clearly under the same principle that Russian majority that lives in eastern part of Ukraine
There was no such majority before Russia's invasion of 2014 (as explained in the other comment). It seems you may be confused by the fact that there were higher numbers voting for pro-Russia parties, or who spoke Russian/Surgyk. But that's not the same as being, or identifying as "Russian" -- any more the fact that English is the dominant language in Ireland means everyone living there must be "English".
This is one of the most important things to understand about Ukraine.