A federal court in Washington D.C. has dismissed a lawsuit filed by the heirs of Dutch painter Piet Mondrian seeking the return of four paintings from the Kaiser Wilhelm Museum in Krefeld, Germany, along with damages for four additional works. The September 30 ruling by Judge Loren AliKhan, appointed by President Biden in 2023, represents a significant legal victory for the German city and its mayor Frank Meyer, who was also reelected in a runoff election just two days earlier.

The 29-page decision from the U.S. District Court for the District of Columbia declared the lawsuit inadmissible in the United States, supporting Krefeld's position on sovereign immunity. Judge AliKhan ruled in favor of the city on a point where it had previously failed before the Higher Regional Court in Düsseldorf. Initially, Krefeld had refused to accept service of the lawsuit, citing sovereign immunity - the international law principle that prevents one state and its subdivisions from being sued in another state's courts.

However, in October 2022, the Düsseldorf court had ordered the city to accept the Washington lawsuit, arguing that sovereign immunity had evolved from an absolute to a relative right due to increasing commercial cross-border activities by state entities. The German court determined that disputes over return claims from hypothetical loan contracts were ordinary civil matters, not sovereign acts.

In the United States, sovereign immunity has been legally regulated and restricted since 1976 through the Foreign Sovereign Immunities Act (FSIA), which provides several exceptions, most notably for commercial activities. The Mondrian heirs' lawsuit relied on an exception for certain unlawful expropriations - specifically cases involving "rights in property taken in violation of international law." Under U.S. jurisprudence, expropriation loses immunity protection if it meets one of three criteria: it served no public purpose, pursued discriminatory intent, or occurred without adequate compensation.

The mysterious history of the eight Mondrian paintings dates back to Paul Wember, the post-war director of the Kaiser Wilhelm Museum, who claimed decades later to have found the works under mysterious circumstances in 1950. When Wember entered four paintings into the museum's inventory in 1954, he left the acquisition circumstances blank, having already sold the other four works. Provenance research has only established that the eight paintings were likely sent to Krefeld in 1929 for an exhibition that never materialized.

Even the hypothesis of a loan contract represents a lenient assumption for Krefeld, as it presupposes the legality of at least the initial possession. According to the lawsuit's theory, an unlawful expropriation occurred either before 1945, when the painter - whose work was branded as "degenerate" - could not effectively reclaim his property, or after 1945, when Wember violated occupation law provisions regarding ownerless artworks. At minimum, the third criterion - lack of compensation - appears clearly fulfilled.

Despite this evidence, Judge AliKhan granted Krefeld immunity based on a narrow interpretation of "taking." In a 2005 precedent involving Amsterdam's acquisition of a Malevich collection in post-war Germany, the same district court had held the city liable. However, in the Krefeld case, the court found no "taking" before 1945, since no state entity had physically seized the forgotten or hidden paintings. After 1945, the court determined that Wember's actions constituted civil law violations that could have been committed by any private individual, lacking the sovereign "public act" element required for expropriation.

This judicial interpretation of sovereign immunity produces the paradoxical result of rewarding the discrete, informal actions of an unfaithful trustee who avoided explicit use of state power. If Judge AliKhan viewed this as an ordinary civil matter, the exception for commercial activities should arguably apply, as the law requires foreign conduct with domestic consequences - conditions met through Mondrian's American will.

The lawsuit's focus solely on the unlawful expropriation exception may represent a strategic weakness. The 2022 Düsseldorf court decision contained critical notes about the complaint's terminology, stating that "wrongfully expropriated" did not align with the actual facts - that the artworks came into the museum's possession with the owner's consent and were subsequently not returned or were sold.

In its press release about the Washington decision, Krefeld summarized what it claimed were the findings of its commissioned provenance report: researchers found no evidence that the works were unlawfully in the city's possession. However, this formulation represents tendentious public relations work. More accurately, the researchers found no evidence of effective ownership acquisition by Krefeld - no contracts for donation, sale, or even mention of such legal transactions. Both the city and politicians from the broad city council coalition carefully avoid speaking of municipal ownership.

The plaintiffs have thirty days to appeal the Washington decision. They can also pursue the newly established arbitration system in Germany for restitution disputes over Nazi-persecution-related cultural property, to which Krefeld has submitted. The 2022 Higher Regional Court provided an important indication that the 2016 U.S. Holocaust Expropriated Art Recovery Act applies not only to officially expropriated artworks but also to those simply lost due to Nazi persecution. Similarly, German public authorities have expanded their definition of persecution-related dispossession in their voluntary commitments. This legal battle over the Mondrian paintings continues to highlight the complex intersection of international law, historical justice, and cultural property rights in post-war art restitution cases.