The US sanctions on ICC operations, announced by Secretary of State Marco Rubio on a Friday, go further than earlier rounds of measures: instead of targeting individual officials, they now target the entire court. For acting chief prosecutor Mame Mandiaye Niang, the consequences are already part of daily life inside the glass building on the outskirts of The Hague, where around 900 staff from 100 nationalities work.

Sanctioned prosecutor locked out of travel and banking

Niang is himself on the sanctions list, and he described the practical effect in personal terms: he was unable to book transport, hotels, or conduct banking operations. When the measures strike the whole institution rather than named individuals, he said, they raise questions about paying staff, running investigations, protecting witnesses and maintaining detention facilities.

That is how Niang framed the situation for an institution that, until now, had seen its senior officials singled out - actions that these latest measures go beyond, targeting the entire court.

A court built on US technology must find alternatives

The dependence runs deeper than banking. The court's own infrastructure, Niang said, relies heavily on American suppliers.

The court is therefore trying to find alternative means, which he acknowledged may not be as effective as the US technology it replaces - an effort he tied to preserving the institution's independence.

The Hague's host obligations and the EU's 'nuclear option'

The host country's obligations are anchored in a "Headquarters Agreement" signed in 2008, under which the Netherlands must protect the court's facilities and staff and ensure its financial freedom from restrictions. Dutch Prime Minister Rob Jetten had vowed at the UN General Assembly last month to defend the ICC "in my country, in my city".

Jetten made that vow in comments just hours before the sanctions were announced, when he pledged to defend the court "brick by brick". The European response is taking shape on two levels:

• •The EU called the sanctions deeply regrettable and said it is "ready to take any necessary measures to enable the court to carry out its work".
• •A possible instrument is the 'blocking mechanism', which would bar European firms from obeying the US sanctions "actively or by deliberate omission".
• •The Netherlands has asked Brussels to prepare that mechanism, which official Berendsen described as the "nuclear option".

What the sanctioned court does

The International Criminal Court, based in The Hague, tries individuals suspected of the world's worst offences: war crimes, crimes against humanity and genocide. Some baseline facts about the institution now under sanction:

• •Established in 2002 by the Rome Statute, it currently has 125 members; the US, Russia, China, India and Israel are not members.
• •It operates under 'complementarity': it can only take on cases a suspect's home country is unwilling or unable to try itself.
• •Since its establishment, the court has convicted 15 people, with four acquitted.
• •Its most high-profile current case is ex-Philippines president Rodrigo Duterte, the first former Asian head of state to stand in the ICC dock.
• •It is distinct from the International Court of Justice, which also sits in The Hague and settles disputes between countries.

The Netherlands has now asked Brussels to prepare the EU blocking mechanism - seen as the 'nuclear option' - while the court tests how far it can run without US systems and banking access.