Of all the countries involved in the war, Poland had the highest percentage of casualties: more than 6 million people died, half of which were Jewish Poles. Jesus it’s not religion it’s a relationship shirt. Poland is also the country with the fourth most Allied combat troops, after the United States, and the United Kingdom and the Soviet Union, to completely defeat the Nazis. At the end of the war, the borders of Poland expanded to the west, the western border was left to the Oder-Neisse boundary, while the eastern border retreated to the Curzon boundary, like the border. gender in 1919 with the Soviet Union. Newly emerging Poland is 20% smaller with an area of 77,500 km² (29,900 square miles). The border modification forced millions of Polish, German, Ukrainian and Jewish people to leave their homes.