The unlawfulness of the Russian military intervention in Ukraine under international law has already been dealt with HERE.
Now it is a time for a short analysis of the Constitution of Ukraine that should cast some light on the lawfulness of a series of events in regard to the Ukrainian crisis in the context of the domestic law.
First of all, the legality of the impeachment of the former President Viktor Yanukovych:
Article 111
‘The President of Ukraine may be removed from the office by the Verkhovna Rada of Ukraine in compliance with a procedure of impeachment if he commits treason or other crime.’
In general the Parliament of Ukraine has right to remove a president from the office. Whether it has been conducted in accordance with the necessary requirements remains impossible to answer so far.
Secondly, the appointment of the new Prime Minister of Crimea, Mr. Sergey Aksyonov:
Article 135
‘The Council of Ministers of the Autonomous Republic of Crimea shall be the government of the Autonomous Republic of Crimea. The Chairman of the Council of Ministers of the Autonomous Republic of Crimea shall be appointed or dismissed by the Verkhovna Rada of the Autonomous Republic of Crimea subject to the consent of the President of Ukraine.’
Although the legality of the office itself is indisputable, the failure to conduct required consultation with the central authorities in Kiev and to obtain the consent of the (interim) President Oleksandr Turchynov, renders the appointment rather unlawful.
Finally, the referendum that is to be held by the local authorities in regard to the independence of Crimea:
Article 73
‘Alterations to the territory of Ukraine shall be resolved exclusively by the All-Ukrainian referendum.’
this should be read in conjunction with the Article 134:
‘The Autonomous Republic of Crimea shall be an integral constituent part of Ukraine and shall resolve issues relegated to its authority within the frame of its reference, determined by the Constitution of Ukraine.’
It is clear that the authorities of the Autonomous Republic of Crimea lack legal capacity to hold a referendum on the subject of independence of the Peninsula. Not to mention that in the history of mankind, there has not been one legitimately conducted referendum in the presence of the Russian (Soviet) troops. They all have resulted in ‘the vast majority wanting to join Russia (Soviet Union)’.