Alright , i know you're not trolling , because it wouldn't make sense , i've seen your posts around here...
"Why would external debt be a reflection on how irresponsibly the government is spending?"
Little buddy....THIS is EXACTLY why everyone hates leftists , for you to have a reference i'll put it this way : you see how stupid and backwards ass conservatives look when they deny climate change? that is exactly how you're looking right now.
When a country defaults on a debt , it gets marked as non-credible , which means that it can no longer take any loans from any private bank or foreign central bank , which means that it has to either cut its expenditure to finance it .... or finance it through money emission (paper money printing) , which causes extreme inflation and in the end...hyperinflation , none of these "wester" countries are sustainable , and they're all gonna default eventually , is just that they're all in it now.
A huge external debt means that your federal government had to take too many loans because it's expenditure is too high , way higher than the tax revenue they collect , that is the literal representation of irresponsibility , do you still fail to understand this???