Twice now, apparently. Tiny Finland, paid its World War I debts fully and on time, in gold no less, during the interwar half-time festivities known as the "Great Depression". Britain didn't end rationing till 1956 - the postwar period was in some ways worse than the war years from what I've read. They more or less "mined" their silver coinage to help pay some of their debts to US, turning to slug coinage. The US didn't follow suit till '65.
One of the only other country to pay us back from WWII is Taiwan.
My parents lived in England from 1951-55, my father was in the USAF. My mother said there were numerous bombed buildings that had been left standing and that their neighbors, they lived off-post, were still heavily rationed.
Britain didn't end rationing till 1956 - the postwar period was in some ways worse than the war years from what I've read.