U.S. President Donald Trump signed an act Wednesday that will place pressure on dozens of countries to recover property stolen from Jews during World War II.

The act, called Justice for Uncompensated Survivors Today — or JUST — Act, requires the State Department to monitor the activities of dozens of European countries on the subject, and then to report to Congress on whether they meet obligations and enact laws and regulations that allow Holocaust survivors to locate their property and demand its return.

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The bill was preceded by a campaign of pressure exerted by an anonymous source that sent hundreds of emails to members of Congress saying the act was an anti-Polish law written in Tel Aviv. Many in Poland are not satisfied with the law, and claim it was intended to pressure Poland to amend a Polish law that would discriminate against Holocaust survivors from Poland in regard to their ability to reclaim property stolen by the Nazis.

Social Equality Minister Gila Gamliel says the law is a "significant innovation," since it "fixes for the first time the issue of the restitution of property as a permanent component, independent of any government policy or policy, in US foreign policy in Europe."

The right-wing media in Poland sharply criticized the law. "Finish this madness; the subject could cost Poland tens of millions" read a headline on a large Polish newspaper. "The Holocaust industry is attacking Poland," read another.

The World Jewish Restitution Organization (WJRO) praised the U.S. president's decision Thursday. "This law makes a clear statement about America's uncompromising commitment to Holocaust survivors and their aspiration for justice," says the organization's operations chief Gideon Taylor.

The law does not give the U.S. any powers to act against any country and does not single out Poland. But Poland is the only country in Europe that has not passed legislation to compensate former owners for assets seized in the upheavals of 20th-century European history, and Warsaw sees itself as the key target of the law.

The Nazis' seizure of Jewish-owned property in Poland during World War II, and the murder of most of Poland's Jewish population, was followed after the war by the Communist state's seizure of large amounts of property that was nationalized. Most of the original owners of that property were not Jewish.

Since the fall of communism, some claimants have regained lost property on a case-by-case basis through courts, but so far Poland has not passed comprehensive legislation regulating the process, creating a situation that has been riddled by fraud and led to a sense of injustice.

Polish Foreign Minister Jacek Czaputowicz says he believes that the U.S. pressure through the JUST Act unfairly sets Jewish claimants above non-Jewish ones, creating tensions within Polish society.