The modern concept of odious debts was first articulated in the post-World War I context, by the jurist Alexander Nahun Sack, in his 1927 book The Effects of State Transformations on their Public Debts and Other Financial Obligations. For Sack, odious debts were debts contracted and spent against the interests of the population of a State, without its consent, and with full awareness of the creditor. Sack (1929) wrote as follows:
“...if a despotic power incurs a debt not for the needs or in the interest of the State, but to strengthen its despotic regime, to repress its population that fights against it, etc., this debt is odious for the population of the State.
“The debt is not an obligation for the nation; it is a regime’s debt, a personal debt of the power that has incurred it, consequently it falls within this power....The reason these ‘odious’ debts cannot be considered to encumber the territory of the State, is that such debts do not fulfill one of the conditions that determines the legality of the debts of the State, that is: the debts of the State must be incurred and the funds from it employed for the needs and in the interest of the State. ‘Odious’ debts, incurred and used for ends which, to the knowledge of the creditors, are contrary to the interests of the nation, do not compromise the latter – in the case that the nation succeeds in getting rid of the Government which incurs them – except to the extent that real advantages were obtained from these debts.”
Sack divided odious debts into several categories:
war debts, subjugated or imposed debts, and regime debts...