The WWI & WWII debt is quite well defined in the UK for example and quite shocking how many years it took to pay off.
Somebody told me that the Italian debt crisis really goes all the way back to Mussolini's excessive prewar spending and in 2011 Berlusconi defended Italy's debt crisis as he argued it went back to the war and was just the way the country runs.
What is the true reason? Given that a country such as Russia managed last year to pay off all the Soviet debt it seems quite strange that a G7 economy like Italy could have a debt going back to Mussulini's era starting in the twentys.
Obviously a countries debt is made up of many things such as public spending and in all countries but chronically in some corruption. But there often is an isolated or small number of decisions, policy or event that accountants for the beginning of the problem.
P.S is this question perhaps for the history stackexchange?
Some historic/economic background is summaried here: https://en.wikipedia.org/wiki/Economy_of_Italy_under_fascism