At the end some participants took each other by the hand; there were cheers, laughter, and applause. When the UN's Global Compact for Migration was agreed at the organisation's New York headquarters in July, after years of tough negotiation, the mood was almost exuberant. However, what was celebrated in New York as an international breakthrough is a subject of controversial debate in Germany. Opponents of the pact claim that it threatens countries' national sovereignty. The German parliament, the Bundestag, has issued an interpretation of the UN Compact that emphasizes, once again, that it does not bind Germany to any legal obligations. It's not that simple, though.
It's true that the compact does not curtail the sovereignty of individual states; but the law works on many different levels. These standards are indeed non-binding, but they can have definite consequences. The set of rules comes under "soft law" — the international legal term for laws that are not currently binding.
Moral pressure to adhere to the rules
This is an instrument for standards that lie in the zone between binding legal norms and non-binding proclamations — a kind of declaration of intent that does not entail legal international sanctions if a country does not abide by the agreed terms. However, even if it's not legally enforceable, it is not, of course, legally irrelevant. A certain pressure exists to abide by the principles of "soft law."
Countries only ever sign up to instruments like these if they endorse their contents, which is why governments generally implement the agreements at home — thereby turning them into domestic law.
In addition, soft law documents provide mechanisms to ensure a degree of compliance: There is often is an obligation to report, and, based on this reporting, rankings are created. So there is moral pressure to implement the standards.
Furthermore, if a legal practice is followed for many years, customary international law can be established. This can lead to "juridification." For example, in 1948 the UN General Assembly adopted the Universal Declaration of Human Rights. Over the years, countries came to the conclusion that these should be legally-binding norms. In 1966, two human rights covenants were adopted at the UN, which are legally binding.
This, though, is a long process. It requires not only the experience of practice, but also the states' legal conviction that a rule should be legally binding. By adopting "soft law" legislation, a country is practically saying that it doesn't want a set of rules to be binding – it will be years before this process of "juridification” can happen. If all states adhere to the rules for long enough, the politically binding will at some point also become legally binding, but it usually takes decades. And here, too, things can get tricky. If the majority of states do not adhere to the UN Compact, then no customary international law will be established, and there will be no obligation for Germany, either.
This paper doesn't really contain anything new for Germany, though, because the European Convention on Human Rights already applies here. If the European Court of Human Rights in Strasbourg decides that, under certain circumstances, an Afghan family may not be deported from Germany to Italy, that decision is legally binding.
The best that could be achieved
To date, none of the critics of the UN migration pact have been able to demonstrate in concrete terms how the Compact for Migration could facilitate this abstract fear of new rights. The idea that the pact could undermine domestic jurisdiction — in contrast to EU law, the Human Rights Convention and the Convention Against Torture — is downright absurd. Migration is a classic cross-border issue; it can only be dealt with internationally. But because states are increasingly reluctant to assume obligations under international law, the Compact for Migration is currently the best that could be achieved.