What did the German leaders believe after World War 1?

They believed they hadn't lost the war on the front (although the Germans had in actual fact been pushed back and retreated on the Western front for months in 1918) but they claimed to have been "stabbed in the back" by Socialist-induced navy mutinies and strikes all over Germany. The bottom line however was that Germany by 1918 simply lacked the manpower and resources to continue the war any longer, let alone win it.