German and Jewish critics alike disparaged the comparison between the modern, Federal German Republic and the "Third Reich" Nazi era of the 1930s and 40s.
The prince "did not intend in any way to trivialize the terrible events of the Third Reich in his private and personal letter" to the head of the Jewish Museum in Berlin, the principality said in a press release.
Hans-Adam II had prompted anger among German and Jewish representatives after writing in a letter revealed Thursday by the Swiss daily Tages-Anzeiger that Liechtenstein already survived "three German Reichs," meaning three eras of attempted German domination in 200 years.
No more art loans for Germany
He hoped also to survive the "Fourth Reich," the prince had continued in his letter written in reply to a request by museum director Werner Michael Blumenthal, who had asked Hans-Adam II to loan him a picture for an exhibition.
On Thursday, Sept. 11, the prince stepped back from his comments, saying that his remarks that the Third Reich should not happen again were not referring to today's Germany.
The exhibition planned for the Jewish Museum is called "Looting and Restitution: Jewish-Owned Cultural Artifacts from 1933 to the Present." It traces the paths of particular artefacts -- including paintings, libraries, china, silver works and photographs -- which were appropriated from Jewish owners during the Nazi regime.
Liechtenstein no longer intended to make its art available for German exhibitions, the prince had written in his original reply to the museum.
Referring to Germany as the "Fourth Reich," he had said his principality did not want to expose its masterpieces to what the prince termed the selective application of constitutional principles in Germany.
German-Liechtenstein relations over the previous 200 years had resembled a roller coaster ride, the prince had said.
Liechtenstein had still been at war with the "Second German Reich" until that monarchy ended before a peace agreement with the principality could be reached, Hans-Adam II's letter said.
He had continued, "Thank God, the Nazi Third Reich had also been wiped out in time" before it had been able to act on its threats to annex Liechtenstein.
German Jews react angrily
However, regarding its relations to Germany, the principality was still waiting for better times, wrote Hans-Adam II.
The Central Council of Jews in Germany reacted with bewilderment and shock to the letter, especially at the prince's apparent comparison of today's Germany with the Nazi era.
"The Prince plays down the Nazi crimes by putting the Federal Republic in one line with the Third Reich," said vice president Salomon Korn.
The Jewish museum also dismissed the prince's letter.
"The comparison of today's Germany and the Third Reich is intolerable", said a museum spokeswoman.
Relations strained by tax investigation
The German ministry of foreign affairs commented that Germany respected international rules of law "of course, also in relation to Liechtenstein.
Ties between Germany and Liechtenstein have been strained especially since German tax investigators probed the principality as a tax haven for Germans seeking to avoid tax payments at home.
The German tax authorities had filed numerous law suits after they received client data by a former employee of Liechtenstein's LGT bank, which he had stolen in 2002.