Thirty-five years ago today, on November 14, 1990 (September 28, 1990 lunar calendar), the Oder-Nice border issue between Germany and Poland was resolved. On November 14, 1990, German Foreign Minister Genscher and Polish Foreign Minister Skubiszewski signed the German-Polish border treaty in Warsaw, the capital of Poland, which finally resolved the Oder-Nice border issue that the two countries had been hanging for 45 years. Historically, large tracts of land east of the Oder-Nice River and the Baltic Sea belonged to Polish territory, which was annexed by German feudalists in 1815. In 1939, the Soviet Union occupied more than 170,000 square kilometers of eastern Poland under the secret Additional Protocol reached by the two sides when they signed an economic and non-aggression treaty with Germany. In February 1945, Fascist Germany was defeated, and Poland was one of the greatest victims of World War II. The Crimean Conference of the United States, the Soviet Union, and the United Kingdom agreed that Poland's loss would be compensated by Germany. In August of the same year, the Potsdam Agreement signed by the United States, the Soviet Union, and the United Kingdom stipulated that more than 100,000 square kilometers east of the Oder-Ness River should be placed under the jurisdiction of Poland. However, a tail was left at that time, stipulating that the final determination of the border should be left to the later signing of a peace treaty with Germany and recognized by the new all-German government. After the division of Germany, which lasted for more than 40 years, a "new all-German government" has not emerged. Although the former GDR signed the Treaty of Görlitz with Poland on July 6, 1950, and officially recognized the Oder-Nice border, the former Federal Republic of Germany refused to recognize it, believing that the Potsdam Agreement did not have the right to cede German territory to Poland. In 1970, the Federal Republic of Germany, in the "Basic Treaty on Normalization of Relations between the two countries" signed with Poland, recognized that "the existing border determined by the Potsdam Conference shall be the western border of Poland" and confirmed its inviolability, but still refused to recognize the "final nature" of the border. The Oder-Nice border issue has always been a focus of debate and a source of tension between Poland and the Federal Republic of Germany. After the issue of German reunification was put on the agenda, Poland worried that a unified Germany would not recognize the border issue and would re-submit territorial claims. Therefore, in February 1990, Poland requested to participate in the "2-4" conference on the reunification of Germany, and asked the two German governments to sign the border treaty with Poland before reunification, and then formally sign it by the unified German government. In order to win the sympathy and support of the Soviet Union, the United States, and the United Kingdom, Poland also launched frequent diplomatic activities. On June 21, 1990, the German and Polish parliaments adopted statements on the German-Polish border issue respectively, guaranteeing that a unified Germany would recognize the existing borders of Poland. On the same day, Chancellor Kohl said in a speech in the Bundestag that the Polish-German border would be the "final border." On July 17, the Polish foreign minister was invited to the "2-4" foreign ministers' meeting in Paris. On September 12, the Treaty on a Final Settlement of the German Question signed at the "24" Moscow Conference stipulated that the Oder-Nice border was a permanent German-Polish border, and that Germany would renounce any territorial claims, thus ensuring that the western border, which covered one-third of Poland's territory, was guaranteed by international treaties.