I agree with your point. There should be some skepticism that debt discourages, rather than encourages war. In more militaristic or authoritarian nations, if the debt were great enough, it could be an incentive to invade the neighbor/nearby country you owe it to in order to destroy it (assuming that scenario).
One of the several reasons Iraq invaded Kuwait, is that Kuwait refused to forgive $14 billion in loans (to Iraq) accrued during the Iran-Iraq war. Iraq's annual GDP in the 1980s was $40b to $60b depending on the year, to give you some idea of their ability to deal with the $14b in debt held by Kuwait (it was a considerable sum to them in the 1980s; it might be like the US owing Panama or Singapore $5 trillion today).
Another point of context, the US spent $2.4T on the Iraq+Afghanistan wars.
Invading Kuwait over $14B debt is a strange leap, since Iraq could far less expensively simply default. Anyway, it's the wrong direction -- $14B debt to Kuwait would make Kuwait less interested in invading Iraq for risk of forcing default. But either way, the value of the oil spoils (in either direction) dwarfs the cost of the debt.
One of the several reasons Iraq invaded Kuwait, is that Kuwait refused to forgive $14 billion in loans (to Iraq) accrued during the Iran-Iraq war. Iraq's annual GDP in the 1980s was $40b to $60b depending on the year, to give you some idea of their ability to deal with the $14b in debt held by Kuwait (it was a considerable sum to them in the 1980s; it might be like the US owing Panama or Singapore $5 trillion today).
https://en.wikipedia.org/wiki/Invasion_of_Kuwait#Dispute_ove...