Recent and pending agreements between Germany and Spain or Greece to regulate the return of migrants to their country of entry do not solve the problem because the law makes it technically impossible to return the migrants. The laws and conventions must be changed so that the migrants could be unconditionally returned to where they came from.
The agreement between Germany and Spain (or Greece) concerns the migrants who have applied for asylum in another EU country before coming to Germany. The agreement is certainly better than ongoing disagreement and as such it will probably be well received, at least in Germany. After all, Angela Merkel needs it at a time when her popularity is steadily declining.
The agreement could perhaps be applied in reality in some cases and migrants will be returned. So far, however, experience has not offered anything to believe that it will function on a large scale, and there is nothing to suggest that this is a solution to the problem.
Those who entered Europe in these recent migration waves are on the territory of Europe, and if they refuse, it is technically impossible for many reasons to return them to where they came from. The new Italian government is trying to fool itself when it promises to return 600,000 migrants. This can’t be done simply because it is technically impossible. This, of course, will have permanent social and political consequences, and those countries that have allowed it will leave it for future generations.
More practical considerations demand that attention be directed to other challenges – how to prevent things that happened from getting worse. Specifically, that requires stopping mass migration, and this possible only by blocking the Union’s external terrestrial borders and protecting the sea border and by unconditionally returning refugees to where they came from. But that would violate current laws and conventions, and that’s why those laws and conventions must be changed. That, however, runs counter to the interestes of those states that support migration. They should be pressured into co-operation, for example by economic sanctions targeted at specific persons responsible.