The EU is telling Trump they will consider the nuclear option, not weapons, US debt. If Trump insists on abandoning Ukraine and throwing them to the wolves of Russia, which would threaten much of Europe, the EU says they will respond by dumping 2.34 trillion of US debt, which if done could destabilize the US economy and in one scenario be like a 2008 scenario for the US.
Remember when the original Taco happened? When Japan and S Korea and others started dumping US debt and the markets tanked and Trump panicked because the bond markets were also imploding? That's what the EU is threatening to do now if Trump sells out Ukraine