It sought to build up the European project as a counterweight to America and to create its independent nuclear force de frappe.

ECONOMIST: Charlemagne

Britain's deterrent costs less than half the amount of France's force de frappe, not least because Britain relies heavily on America to provide Trident missiles and even components for its warheads.

ECONOMIST: The decision to renew Trident was a foregone conclusion

This is remarkable, given the different approaches that France and Britain have taken towards their nuclear deterrents (Britain depends heavily on American kit, while France's force de frappe is a supreme symbol of national sovereignty).

ECONOMIST: The Anglo-French defence pact