1957 Chief of Naval Operations Arleigh Burke and First Sea Lord Louis Mountbatten began corresponding on the project. After the cancellations of the Blue Streak and Skybolt missiles in the 1960s, under the 1962 Nassau Agreement that emerged from meetings between Harold Macmillan and John F. Kennedy, the United States would supply Britain with Polaris missiles, launch tubes, ReBs, and the fire-control systems. Britain would make its own warheads and initially proposed to build five ballistic missile submarines, later reduced to four by the incoming Labour government of Harold Wilson, with 16 missiles to be carried on each boat. The Nassau Agreement also featured very specific wording. The intention of wording the agreement in this manner was to make it intentionally opaque. The sale of the Polaris was malleable in how an individual country could interpret it due to the diction choices taken in the Nassau Agreement. For the United States of America, the wording allowed for the sale to fall under the scope of NATO's deterrence powers. On the other hand, for the British, the sale could be viewed as a solely British deterrent. The Polaris Sales Agreement was signed on April 6, 1963. In return, the British agreed to assign control over their Polaris missile targeting to the SACEUR (Supreme Allied Commander, Europe), with the provision that in a national emergency when unsupported by the NATO allies, the targeting, permission to fire, and firing of those Polaris missiles would reside with the British national authorities. Nevertheless, the consent of the British Prime Minister is and has always been required for the use of British nuclear weapons, including SLBMs. The operational control of the Polaris submarines was assigned to another NATO Supreme Commander, the SACLANT (Supreme Allied Commander, Atlantic), who is based near Norfolk, Virginia, although the SACLANT routinely delegated control of the missiles to his deputy commander in the Eastern Atlantic area, COMEASTLANT, who was always a British admiral. Polaris was the largest project in the Royal Navy's peacetime history. Although in 1964 the new Labour government considered cancelling Polaris and turning the submarines into conventionally armed hunter-killers, it continued the program as Polaris gave Britain a global nuclear capacity—perhaps east of Suez—at a cost £150 million less than that of the V bomber force. By adopting many established, American, methodologies and components Polaris was finished on time and within budget. On 15 February 1968, , the lead