The United Kingdom and France unveiled the Northwood Declaration on 10 July, pledging for the first time to coordinate the use of their independent nuclear deterrents. Prime Minister Keir Starmer said the accord ensures that “any extreme threat to Europe would prompt a response from both our nations,” while President Emmanuel Macron called the move “historic.” Although each arsenal remains under national control, the declaration states they “can be coordinated” and sets up a bilateral Nuclear Steering Group to align policy, capabilities and operations. Bringing together Europe’s only two nuclear-armed states, the pact pools roughly 500 warheads—about 225 held by Britain and 290 by France—and is intended to strengthen European security amid rising tensions with Russia and uncertainty over future U.S. commitments. The agreement also envisages shared early-warning data and joint drills, expanding a defence relationship first formalised under the 2010 Lancaster House treaties. In a related step, French Armed Forces Minister Sébastien Lecornu confirmed that MBDA will restart full-rate production of the Franco-British Storm Shadow/SCALP-EG air-launched cruise missile later this year, placing the first domestic order in 15 years. The decision, supported by London, will replenish inventories depleted by deliveries to Ukraine and feed into the next phase of the Future Cruise/Anti-Ship Weapon programme. Officials on both sides argue that the parallel initiatives on nuclear doctrine and advanced conventional weapons demonstrate a renewed Franco-British commitment to modernise Europe’s high-end deterrence while preserving national sovereignty, sending what Starmer termed a clear signal of unity against “any extreme threat” to the continent.