Why the Netherlands and why not the ICC?

On 24 February 2022, Russia invaded Ukraine. Whilst the International Criminal Court (ICC) prosecutes crimes under international law such as war crimes, crimes against humanity, genocide and the crime of aggression, the ICC generally has no jurisdiction if neither the attacking nor the attacked state is a party to the Rome Statute. [1] In February 2022, neither Russia nor Ukraine was a member of the ICC in The Hague.[2] It was only after the invasion that Ukraine acceded to the Rome Statute and became a member of the ICC on 1 January 2025. [3]

In the context of the conflict in eastern Ukraine, Ukraine – as a non-member – had granted the Court jurisdiction for limited periods on the basis of Article 12(3) of the Rome Statute. The second declaration of this jurisdiction is valid for an indefinite period and thus also covers acts committed from 24 February 2022 onwards. [4] However, this declaration does not grant the International Criminal Court jurisdiction over the crime of aggression. The Rome Statute prohibits the International Criminal Court from prosecuting this crime if it was committed by nationals of, or on the territory of, a non-State Party (Article 12 up to (5)) or if jurisdiction has not been previously conferred by the UN Security Council (Article 15).[5]

With Russia’s war of aggression against Ukraine, one member of the Council of Europe has attacked another. [6]

However, under the principle of state immunity applicable under international law, the Russian leadership – comprising President Vladimir Putin, Prime Minister Mikhail Mishustin and Foreign Minister Sergey Lavrov – cannot be prosecuted before the courts of other states, such as those of Ukraine, at least whilst they remain in office.[7][2] This immunity does not, however, apply before international courts, as these exercise the punitive powers of the international community. [2] As a corresponding resolution by the UN General Assembly is unlikely to secure a majority, but a regional exception to immunity for the crime of aggression appears to be emerging in Europe, and the vast majority of Council of Europe members – including Ukraine and Russia – criminalise wars of aggression in their national laws, a European tribunal could override the defendants’ immunity.[2]

https://de.wikipedia.org/wiki/Sondertribunal_für_das_Verbrechen_der_Aggression_gegen_die_Ukraine (translated using DeepL)