10 air-defense sites, and 28 IRBM sites. The degree of cooperation was such by the Cuban Missile Crisis that RAF officers visiting SAC headquarters in Nebraska reported being "treated just like Americans. We went all through their briefings, computers, top secret rooms and so forth". While some British officers emphasized the continuing importance of maintaining the ability to act alone with an independent deterrent if necessary, by 1962 the independent list was essentially the RAF portion of the joint plan and no active training was done. The British emphasis on retaining an independent capability, however, continued over several decades and changes in government. As the Defence Council stated in 1980, While current United Kingdom's nuclear forces—four Trident s—are strictly under UK national control, they had two distinct roles under the SIOP. The first was part of a UK-only retaliatory response to a nuclear attack, whether a full strategic strike, or a limited tactical strike. The second role was one in which the Royal Navy participated in the SIOP, in effect becoming an extension of the U.S. Navy's Trident submarines. This role was to be part of a NATO response to a Soviet nuclear strike. The Royal Navy's contribution to the SIOP was small. The four Vanguard submarines could strike a maximum of 512 separate targets; equivalent to 7% of the total U.S. nuclear strike capacity. SIOP in fiction In Dale Brown's novel Plan of Attack, it is revealed that Patrick McLanahan is one of the most highly valued personnel in the U.S. military because of his involvement in classified projects and knowledge of the American SIOP. However, because of McLanahan's involvement in controversial highly classified military actions, President Thorn largely ignores this fact and the warning of an imminent Russian attack until Russia launches a nuclear campaign against the US. In Eric L. Harry's novel Arc Light, the President decides to execute "SIOP 6-C" in a counterforce strike against Russia after a Russian general gained control of the nuclear codes and launched a massive attack against the US. In the book, "SIOP 6-C" had six thousand nuclear warheads assigned to be used, some of which were held in reserve. In William Prochnau's novel Trinity's Child, a Soviet nuclear sneak attack triggers US retaliation. There is discussion of SIOP among the unnamed US President, the military commander codenamed Alice on board the SAC Looking Glass aircraft who is advising the President,