Some consequences stand out if Le Pen wins: 1) NATO: France would stay a member but become less reliable. Macron's offer of a European dimension to French nuclear deterrence would likely end. 2) Ukraine: France would move from being a co-leader to being a brake. 3) EU: veto-player at a critical moment. She no longer advocates Frexit or leaving the euro. Instead, she favours a constitutional push to make French law take primacy over EU law. 4) Defence-industrial policy: "strategic autonomy" would turn national. The National Rally supports higher defence spending, but through French sovereign industry, not Commission-led instruments. The paradox is that Europe would get more French defence capability but less European defence integration. 5) JEF would become a hedge against France as well as the US. The ten members (the UK, the Nordics, the Baltics and the Netherlands) already value it as a fast, flexible format that isn't hostage to unanimity in Brussels or Washington. With Paris unreliable on Ukraine and deterrence, northern Europe would lean on it harder. 6) Britain's pivot partner would weaken. The UK runs a two-track European defence strategy: JEF in the north, France for high-end capability and the nuclear dimension. Several UK-France arrangements would be at risk. 7) France's own competing format to JEF would wither. The French-led European Intervention Initiative (EI2) overlaps heavily with JEF membership. Under Le Pen, it would likely lose political drive. That would remove one of Paris's main channels into northern European security thinking, leaving JEF largely unrivalled. 8) The Franco-German axis would shift toward Berlin–London. With France turning inward, Germany would become the natural continental anchor.