This is so true, lol.
As to why they didn't just pay it back instead of lending in the first place, the country usually actually owes businesses within the other country, not the other country itself.
Basically,
Country A borrows money from Businesses in Country B
Country B can't borrow the money from it's own businesses, that would be taxes, so they borrow money from businesses in Country A.
When the debt outlasts the business, it is said to be owned by the country the business was placed in, when in reality, it is owned by the descendants of the owners of the business, who may or may not exist at this point, and may in fact, have already moved to the country that borrowed the money.
Please keep in mind, this is how my father explained it to me when I asked how we can owe France and France can owe us from way back in our respective revolutionary wars, and why we didn't just say that the debts cancelled... My father being a reasonably intelligent man, and my mother being a history major who didn't contradict him, kinda leads me to think they weren't saying this for nothing.
Is *your* head spinning yet? Mine sure as hell did the first time I heard all that.