Through "Project Syndicate" (see above), I also discovered a piece by old friend Varoufakis:

Solidarity Is Not What Europe Needs - Yanis Varoufakis - Project Syndicate

The idea for such bonds is neither new nor complicated. What is new is that, during this pandemic, the call for Eurobonds was couched in terms of solidarity with the stricken southerners.

... The outcome isn't hard to explain. The nine heads of government gambled that their portrayal of the bonds as the financial embodiment of European solidarity would win the day. It was a bad bet.

... Alas, Hoekstra is right: Solidarity is a poor justification for Eurobonds or any other form of debt mutualization. When I encounter suffering individuals or communities, I may feel compelled to give money, offer shelter, or provide a large, long-dated, cheap loan when no bank will help. That's solidarity. But solidarity does not, and cannot, compel me to go into debt with them.

So far I can follow but in the end the pleas to rationality re. "Euro was made [artificially] cheaper and better for Northerners by soft-currency Southerners" is a bit weak.

Dutch and German savers need to recognize that their savings would be much, much lower had indebted Italians, Greeks, and Spaniards not shared the euro with them. After all, it is southern deficits that keep the euro's exchange rate low enough for Germany and the Netherlands to maintain their net exports. Eurobonds' merit thus has nothing to do with solidarity. By shifting debt from deficit countries to a strong Union and, in the process, shrinking total eurozone debt (thanks to the lower long-term interest rates implied by the EU's greater creditworthiness), Eurobonds would keep a country like Italy in the euro - thereby preventing Dutch and German savings from vanishing.

... The way to avoid northern vetoes is to appeal to what Smith would call their "self-love," while making it clear that self-harming northern policies also will be vetoed.

That one doesnt 'hold much currency' with the Northerners, either. There needs to be something easier and more convincing. Something like investment that will pay for itself. Or full monetization no problem, I don't know.

_{Schengen is toast!}