France, Feb. 15 -- With Russia's war in Ukraine fuelling fears of a wider threat and uncertainty lingering over Washington's long-term security commitments, the debate over nuclear deterrence has moved decisively into the political mainstream. Across Europe, governments are weighing how to strengthen their defences - and whether a more distinctly European nuclear role is now unavoidable.

Against this shifting backdrop, French President Emmanuel Macron has stepped forward with a signal that Paris may be ready to lead. Speaking at the Munich Security Conference this weekend, he said he was considering a doctrine that could include "special cooperation, joint exercises, and shared security interests with certain key countries".

The comment...