What was the country that was the only nation to pay off its World War I debts to the United States? This nation fell to a Soviet invasion in 1939-1940.

Finland

The country that was the only nation to pay off its World War I debts to the United States is Finland. Finland achieved its independence from Russia in 1917 and subsequently fought against Soviet Russia in the Finnish War of Independence. During World War I, just like many other countries, Finland had borrowed money from the United States to support its war efforts.

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