Why did germany and japan place the blame on other countries for their economic downturns during the great depression, and how did this inevitably lead to the second world war?

The Great Depression was an economic slump in North America, Europe, and other industrialized areas of the world that began in 1929 and lasted until about 1939. It was the longest and most severe depression ever experienced by the industrialized Western world.

Though the U.S. economy had gone into depression six months earlier, the Great Depression may be said to have begun with a catastrophic collapse of stock-market prices on the New York Stock Exchange in October 1929. During the next three years stock prices in the United States continued to fall, until by late 1932 they had dropped to only about 20 percent of their value in 1929. Besides ruining many thousands of individual investors, this precipitous decline in the value of assets greatly strained banks and other financial institutions, particularly those holding stocks in their portfolios. Many banks were consequently forced into insolvency; by 1933, 11,000 of the United States' 25,000 banks had failed. The failure of so many banks, combined with a general and nationwide loss of confidence in the economy, led to much-reduced levels of spending and demand and hence of production, thus aggravating the downward spiral. The result was drastically falling output and drastically rising unemployment; by 1932, U.S. manufacturing output had fallen to 54 percent of its 1929 level, and unemployment had risen to between 12 and 15 million workers, or 25-30 percent of the work force.