Trade wars are becoming a reality. After a short period of apparent detente, US President Donald Trump recently declared that Washington is ready to levy tariffs on Chinese imports for $50bn, as well as broader investment restrictions. Now, trade talks have come to an impasse: the US Administration will also impose steel and aluminum tariffs on the European Union, as well on Mexico and Canada. As Trump’s trade blows are hardening, the resolve among the US’ competitors – as well as among the US' closest allies – to fight back, a trade war has been ignited. What will the medium and long-term consequences of this escalation be? What is at stake for the international actors involved, including the US? And how can, or should, countries react to the changing rules of international trade?