Payments (outflows) require income (inflows). It gets worse than that in interactions between a lender from a rich country and major investment projects in a poor country. The poor country can get totally screwed over.
German banks got into these relationships.
See, I actually studied the S&L collapse in the USA in the 1980’s. The temptation to make bad loans is there for many of us.
And it looks like Greece had politicians willing to put other people on the hook for what they borrowed, but it took German participation for make it happen.
The Greek people are being blamed for a bad deal made by elites in both countries. That is unfair.