It’s pretty clear that America caused the financial crisis, but we can feel a bit better about the Great Depression.
NBER’s Doug Irwin says France set of a wave of worldwide deflation by hoarding gold:
This “gold hoarding” created an artificial shortage of reserves and put other countries under enormous deflationary pressure. Counterfactual simulations indicate that world prices would have increased slightly between 1929 and 1933, instead of declining calamitously, if the historical relationship between world gold reserves and world prices had continued.
Other theories have blamed the depression on tightening of US monetary policy in 1928.