The North Atlantic Treaty, signed in Washington on 4 April 1949, was always a fundamentally maritime arrangement. Although at first it seemed that the major strategic priority was tying US long-range strategic nuclear air power to a more credible defence of Western Europe, the title of the organisation it set up, the North Atlantic Treaty Organisation(NATO), demonstrated that the foundation of the alliance was the ability of the USA – and Canada – to project their military power across a major maritime space, the Atlantic Ocean. The Alliance also contained the other main Western European naval powers, Britain, France and the Netherlands.

The Medium Term Defence Plan adopted by the Alliance's Military Committee in 1949 stressed successful defence against any Soviet attack and then moving forward to offensive operations that would eventually achieve war termination on the Alliance's terms. This campaign would be supported by control of North Atlantic sea and air lines of communication. In October the North Atlantic Regional Planning Group with representatives from the USA, Britain, France, Canada, Denmark, the Netherlands, Norway, Belgium, Portugal and Iceland was tasked with drafting plans for a unified defence of the North Atlantic area.

There were five planning sub-groups, the first on offensive operations. This sub-group was formed only of US and British representatives although there was a permanent French observer. Its task was: “To prepare broad plans for offensive action against enemy armed forces and shipping, their bases and port facilities, including attack at source, amphibious and airborne operations and offensive mining.”