The EU Treaties remain integrated into worldwide (e.g. UN, GATT, WTO) and regional treaties of EU member states (like the ECHR) as integral parts of European integration. The geopolitical changes caused by authoritarian power politics, climate change, the digital revolution and the emergence of a multipolar world with “pluri-crises” have reinforced the EU’s internal integration; the EU’s external integration with third countries practising authoritarian or neoliberal policies are, however, confronted with disintegrating value conflicts: the more trading partners become geopolitical rivals and potential military adversaries, the more the EU prioritizes strategic autonomy by using the EU’s regulatory might (“Brussels effect”), “security exceptions” and unilateral countermeasures for de-risking global value chains, limiting economic integration and “decoupling” dependencies on authoritarian governments. This contribution describes disintegrating developments transforming the UN and WTO legal systems into a new geopolitical order. Europe’s multilevel republican, democratic and cosmopolitan constitutionalism has, so far, promoted constructive internal EU crises responses and external EU leadership for plurilateral UN and WTO sustainable development reforms. The constitutional diversity among authoritarian power monopolies, constitutional nationalism and Europe’s multilevel constitutionalism drives international legal policy competition, lawfare and regulatory rivalries requiring a new security system. Yet republican constitutionalism (like multilevel trade and investment adjudication) continues to promote sustainable development governance. It appears doubtful whether the UN, WTO and EU legal systems are fit for the “crises governance” and “EU strategic autonomy” necessary for protecting the sustainable development goals.