Invocation of International (Treaty) Law Principles Against an Aggressor State: Suspension, Restriction of Membership Rights, Expulsion?

The research aims at the invocation of the main principles of international law and treaty law, in particular, pacta sunt servanda, bona fide, jus cogens and the rule of law, in order to support the right to suspend, limit or restrict membership rights of Russia in treaties and international organizations in the context of aggression against Ukraine. The authors seek to demonstrate that the principles allow for certain measures to be taken against a State manifestly and flagrantly violating international law and to present this principle-based reasoning with a reference to the United Nations and the UN Charter. The contents of the listed principles are revealed demonstrating that they contain specific countermeasures regarding treaty participation and organization membership that may be invoked against the aggressor State. The authors emphasize that international law has always evolved around unprecedented events following universal legal values, and aggression against Ukraine obliges members of the international community to undertake responsibility and use international law solutions, including invocation of international (treaty) law principles in order the aggressor State does not benefit from grave breaches of international law and progressive development of international law is being ensured.