Why can't Poland take Germany to court for WW2 crimes?
Why can't Poland raise WW2 claims in court?
A common question people ask is a variation of "if Poland or Poles were harmed, why doesn't Poland take Germany to court?"
To raise claims and to hear your case in court, you must find a court that has jurisdiction to hear the claim. If there is no court with jurisdiction, both parties must consent to arbitration or negotiations.
In short, the International Court of Justice, the International Criminal Court, the European Court of Human Rights, the Court of Justice of the European Union and the United Nations Security Council do not have jurisdiction to hear the claims, and Germany is unwilling to consent to arbitration in the Permanent Court of Arbitration or any other ad hoc or international tribunal.
The International Court of Justice - no jurisdiction
State v State claims
Poland cannot raise claims against Germany for the harm Poland suffered in WW2 as Germany excludes the ICJ from hearing WW2 claims. Germany's declaration to the ICJ states that it accepts the ICJ's jurisdiction except for conflicts that arise "from or is connected with the deployment of armed forces abroad, involvement in such deployments or decisions thereon"; this is understood broadly as including WW2.
Individual v a State
The legal doctrine of state immunity prevents an individual from raising claims against a state.
Therefore the ICJ cannot hear Poland's claims.
The International Criminal Court - no jurisdiction
The ICC's document "The ICC at a Glance" states: "The ICC has jurisdiction over the most serious crimes of concern to the international community as a whole, namely genocide, crimes against humanity and war crimes, when committed after 1 July 2002."
Therefore, the ICC cannot hear Poland's claims
The European Court of Human Rights - no jurisdiction
The ECHR's document "The ECHR in 50 questions" states that the ECHR "has jurisdiction to hear allegations of violations of the European Convention on Human Rights" which entered into force on 3 September 1953.
The ECHR's "Practical Guide on Admissibility Criteria" states "the provisions of the Convention do not bind a Contracting Party in relation to any act or fact which took place or any situation which ceased to exist before the date of the entry into force of the Convention in respect of that Party".
Therefore, the ECtHR cannot hear WW2 claims.
The Court of Justice of the European Union - no jurisdiction
According to the EU's webpage on the CJEU, "The Court of Justice of the European Union (CJEU) interprets EU law to make sure it is applied in the same way in all EU countries, and settles legal disputes between national governments and EU institutions."
Therefore, as the CJEU only adjudicates on EU law that was enacted after WW2 and after the EU was formed, the CJEU cannot hear WW2 claims.
The United Nations Security Council - no jurisdiction
According to the UN's webpage, the UNSC's purpose is "to maintain international peace and security; to develop friendly relations among nations; to cooperate in solving international problems and in promoting respect for human rights; and to be a centre for harmonizing the actions of nations."
Therefore, the UNSC is not a forum where you can directly raise claims against another country.
The Permanent Court of Arbitration
Under the PCA Arbitration Rules 2012, in the Optional Rules for Arbitrating Disputes between Two States (1992), it states in Article 1, "Where the parties to a treaty or other agreement have agreed in writing that disputes shall be referred to arbitration under the Permanent Court of Arbitration Optional Rules for Arbitrating Disputes between Two States, then such disputes shall be settled in accordance with these Rules subject to such modification as the parties may agree in writing."
As arbitration under the PCA can only start with the agreement of both parties, i.e. Poland and Germany, it is very unlikely that the PCA will be a forum to hear WW2 claims.
Ad Hoc or Special International Tribunals
Many ad hoc or special international tribunals have been set up, including the Nuremberg Trials, to hear specific claims and adjudicate on them.
However, for the same reason as above, i.e. likely requiring Germany's agreement, it is very unlikely to hear WW2 claims in an ad hoc or special international tribunal.