The statement that best evaluates why domestic issues in Europe contributed to World War II is: "Poor economic conditions allowed the rise of Hitler and other aggressive leaders."
This statement highlights the significant role that the economic turmoil of the 1920s and 1930s, particularly the Great Depression, played in destabilizing European nations. This instability created a fertile ground for extremist political movements, including the rise of Adolf Hitler in Germany, which ultimately contributed to the onset of World War II.