如何实现英国核力量的现代化，是继续改进既有的核导弹系统，还是从美国购买新一代系统，是玛格丽特·撒切尔担任英国首相之后面临的政策抉择。出于巩固英美军事政治同盟关系的考虑，撒切尔政府最终选择了与美方达成"三叉戟"导弹协议。该协议比以往双方缔结的协议更加有利于英国，美国也实现了自己的目的，从而不但使英美核同盟关系，而且使英美"特殊关系"，上升到了一个新的历史高度。

To achieve the modernization of the UK's nuclear forces,Margaret Thatcher had to make a choice after she had became the Prime Minister whether continue to improve the existing nuclear missile system or purchase a new generation system from the US. Finally,Thatcher chose to conclude the "Trident" missile agreements with the US in order to consolidate the military-political alliance between the UK and US. These agreements were more conducive to the UK than previous ones,and the US also achieved its own goals,which has helped to raise both the Anglo-American nuclear alliance relationship and the "special relationship" between the UK and US to a new historical height.