The Treaty of Versailles forced Germany to pay all the reparations from WW1, which diminished their economy. They were able to pay for the 1st year, but by the 2nd year, their economy had dropped so low that they could not afford to pay again. The US then came up with the Dawes Plan to help support Germany's economy by allowing them a $200 million loan to repair themselves, as well as pay the reparations in small increments at a time. Soon after, the Great Depression came and pretty much almost all European economies dropped, perhaps except for the Scandinavian countries.
Arguing that he would rather have “birds than airplanes,” in the 1960s, Lindbergh threw his support behind the World Wildlife Fund and the International Union for Conservation of Nature and Natural Resources.