On June 25, an agreement was signed in Kyiv between Ukraine and the Council of Europe to establish a new tribunal for investigating aggression crimes within Ukraine.

President Volodymyr Zelensky, speaking at the signing ceremony alongside Council of Europe Secretary General Marija Pejčinović Burić, stated: “Justice takes time, but it must be achieved.”

Last month, the European Union also expressed support for the tribunal's establishment in Lviv.

But what exactly is a crime of aggression? What role does the Special Tribunal play? How is it different from the International Criminal Court (ICC)?

Here are eight key points to understand about what the tribunal can and cannot do.

What is a crime of aggression?

According to the ICC's definition, a crime of aggression is the “use of armed force by a state against the sovereignty, territorial integrity, or independence of another state.”

This means that the leadership of the state initiating the invasion is subject to prosecution.

This is one of the four core crimes defined by the Rome Statute: genocide, crimes against humanity, war crimes (serious violations of the Geneva Conventions), and finally, the crime of aggression.