Now we evaluate the legality of this act. According to the “Stalinist” Constitution of the USSR (1936), we have:
Article 18. The territory of the Union republics cannot be changed without their consent.
As we see, the norm of the Basic Law of the USSR does not specify how this consent should be formalized. Therefore, we look at the Constitution of the RSFSR (1937) and find:
Article 19. The jurisdiction of the Russian Soviet Federative Socialist Republic on the person of its highest authorities and government bodies is subject to
c) the submission for approval of the Supreme Soviet of the USSR of the formation of new territories and regions, as well as New autonomous republics and regions within the RSFSR;
d) approval of the boundaries and regional divisions of autonomous Soviet socialist republics and autonomous regions;
e) the establishment of boundaries and regional division of territories and regions;
Article 22. The highest body of state power of the RSFSR is the Supreme Soviet of the RSFSR.
Article 23. The Supreme Soviet of the RSFSR exercises all rights conferred by the RSFSR in accordance with Articles 13 and 19 of the Constitution of the RSFSR, since they do not enter into the competence of the RSFSR bodies accountable to the Supreme Soviet of the RSFSR: Presidium of the Supreme Soviet of the RSFSR and the Council of People’s Commissars of the RSFSR and the People’s Commissariats RSFSR.
Article 24. The Supreme Soviet of the RSFSR is the only legislative body of the RSFSR.
Thus, the consent of the RSFSR required by Article 18 of the USSR Constitution to change its borders should have been granted by its Supreme Soviet, and the Presidium of the Supreme Soviet of the RSFSR had no such right. Moreover, even the powers of the Supreme Soviet of the RSFSR did not allow doing so, since in the Constitution of the RSFSR this government body was only allowed to change the administrative boundaries within the RSFSR territory. With great stretch, it is likely possible to recognize the transfer of the Crimean region to the Ukrainian SSR, which is within the authority of the Supreme Soviet of the RSFSR, but it had not adopted such a law at the time. There was only a Resolution of the Presidium of the Supreme Soviet of the RSFSR.
Consequently, by decree of the Presidium of the Supreme Soviet of the USSR of February 19, 1954, an illegal legal act of the RSFSR was approved.
Now we will check with the then USSR Constitution :
Article 30. The highest body of state power of the USSR is the Supreme Soviet of the USSR.
Article 31. The Supreme Soviet of the USSR exercises all the rights assigned to the Union of Soviet Socialist Republics under Article 14 of the Constitution, since they do not enter into the competence of the USSR organs of the USSR Supreme Soviet, USSR Council of Ministers and USSR ministries accountable to the USSR Supreme Soviet.
Now let us look here:
Article 14. The jurisdiction of the Union of Soviet Socialist Republics represented by its highest bodies of state power and bodies of state administration are:
e) approval of changes in the borders between the Union republics;
We see that the Presidium of the USSR Supreme Soviet did not have the right to transfer the Crimean region from the RSFSR to the Ukrainian SSR. This question had to decide the USSR Supreme Soviet.
So, in the period from 1954 to 2014, Ukraine owned the Crimea illegally and therefore cannot claim it now.
In the Ukrainian Wikipedia, however, we can find that the above reasoning (without details) was called a "myth." I believe that this statement does not hold water. In a separate note, I will logically and flawlessly show that Ukrainian authors are trying to pull an owl on the globe. That is because why they omitted essential details proving the illegality of the transfer of Crimea to the Ukrainian SSR in 1954.
To be continued (article titles may vary).