What policies would you recommend to Italy and Germany, assuming their desire to achieve a sustainable society?

The policies I would recommend to Italy and Germany would be that of territorial aggrandizement. It worked so well in WW2 that I would heartily recommend that they try it again.

Immigration seems the easiest way to battle declining populations in Italy and Germany. If they want to sustainability. They may prefer to downsize a bit.

I would recommend a policy of birth control to help control the population increase.

I would recommend a growth infra structure be build to prepare themselves for growth and the economy.

I would tell Germany and Italy to look at 2 countries. Ireland and Iceland. Iceland only took 2billion loan, burned their bond holders and formed new banks. Employment is picking up and they are doing ok. Ireland owes the EU about 180 billion. Refuses to burn their bond holders and guarenteed their bank. No on is working an people is emigrating.

In Germany and Italy, I would recommend an increasing retirement age to encourage people to work for more years of their life. This should be perfectly reasonable as aging populations have increasing numbers of individuals remaining healthy and capable well past previous retirement ages. I would also encourage full employment and discourage unemployment.