CB: Maybe the idea is that war can be one form of creative destruction and depression is another; not so much that depression causes war ? A depression is a devalorization itself. Great Depression was devalorization. WWII was revalorization for the US, and further devalorization (creative destruction) for Europe.
War also is a way to pit the workers of different nations against each other to avoid revolution within a nation. Thus the Bolsheviks opposed the war adamently, and criticized the German Social Democrats. It back fired in Russia in WWI 'cause they had Bolsheviks. US Cold War and hot wars in the same period had this motive especially.
Also, post WWII imperialist wars were to open markets or reopen markets in former colonies and semi-colonies.