1948至1951年，中国内部政治局势发生变化，与此相关，英国在华撤侨行动由初始决策、小规模开展、停滞不前到大规模完成，经历了反复的协调与考量。英国对撤侨问题的权衡，主要基于中英关系的发展趋势及保护英国在华利益两方面考虑，与当时的国际形势、中国内部政治形势与外交政策密切相关。中共对在华英侨的态度及政策变化是促使英国出台撤侨计划的重要原因。中华人民共和国成立前，中共中央对在华英侨及其产业多以保护为主；此后，中国政府采取了较为谨慎的政策，是特定历史环境下的政治选择。

1949年4月，在长江上发生了英国军舰同解放军冲突事件，英国海军船舰撤出上海，英国与中共关系一度恶化，这成为英国在华撤侨规模扩大的重要转折点。1949年5月，英国驻广州领事发表撤侨警告信，明确提出认真考虑撤离家属和那些被视为“非必要”的人员，标志着英国在华撤侨政策的最终确定。英国撤走在华侨民是一个由点到面，由部分带动整体的过程，上海便是此过程中较早开启撤离进程的重要城市。上海防卫计划作为特殊时期英国对海外民众的应急保护计划，安抚了在沪英侨的焦虑情绪，为后续可能发生的危险提供了预警方案。但撤侨过程缓慢，英国不愿放弃在华庞大的商业利益是撤侨事宜难以推进的核心因素。1949年10月，中华人民共和国正式成立，政权也逐渐稳固，英国也于1950年初宣布承认中华人民共和国，频频向中共示好，但又因为自身立场不明而未建立正式的外交关系。在此阶段，英国官方仍然没有坚定撤离侨民的态度，反而期望因他国撤侨而强化英国在中国的影响力，最关心的仍是在华经济利益。1950年6月，英国与中共在朝鲜问题上形成了对立局面。此后，中英关系急转直下，中方对英侨在华的合法地位予以否认，这引起了侨民群体的普遍恐慌，英侨在此时不得不撤离。1951年底，中国境内英侨人数已不足千人；1954年，英资产业基本退出中国市场。

Between 1948 and 1951, the internal situation in China was turbulent, and the British evacuation of Chinese nationals from China went through repeated coordination and consideration from initial decision-making, small-scale implementation, stagnation to large-scale completion. Britain's weighing of the issue of evacuation was mainly based on the development trend of Sino-British relations and the protection of British interests in China, and was closely related to the international situation, China's internal political situation and foreign policy at that time. The CCP's attitude towards the British nationals in China and the change in its policy were the major reasons that prompted the UK to introduce the evacuation plan. The Communist Party's Central Committee of China (CPC) was mainly concerned with protecting British expatriates and their industries,under the general environment of economic blockade and diplomatic isolation, the new Chinese attitude was prudent, and the harsher approach taken towards British enterprises and businessmen in China was a political choice in the specific historical environment. Considering its huge economic interests in China, the UK not only introduced the policy of "maintaining a foothold" in China, but also took the lead in making preparations for recognizing the new CCP regime.

In April 1949, the "Amethyst" incident broke out, British naval vessels were withdrawn from Shanghai, and the relationship between the UK and the CCP deteriorated for a while, which became an important turning point for the expansion of the scale of the UK's evacuation of Chinese nationals. In May 1949, the British consul in Guangzhou issued a warning letter on evacuation, clearly mentioning that serious consideration should be given to evacuating family members and those deemed "non-essential", marking the finalization of the British policy of evacuating Chinese nationals in China. The evacuation of British nationals from China was a point-to-point process, whereby the whole was driven by the parts, and Shanghai was an important city that started the evacuation process early in

the process. The Shanghai Defence Plan, as an emergency protection plan for the British overseas population during the special period, soothed the anxiety of the British expatriates in Shanghai and provided an early warning of possible dangers. However, the slow pace of evacuation and Britain's unwillingness to give up its huge commercial interests in China were the core factors that made it difficult to move forward with the evacuation, and the establishment of the Communist Party of China (CPC) in October 1949 and the gradual stabilization of the CPC regime, Britain declared that it recognized the new China 1950's and made frequent gestures of goodwill to the CPC, but failed to establish formal diplomatic relations due to the lack of clarity about its own position. At this stage, the British officials were still not determined to evacuate its nationals, but expected to strengthen its influence in China by evacuating its nationals from other countries, but its main concern was still its economic interests in China. After that, China and British relations took a sharp turn for the worse, and the Chinese denied the legal status of British expatriates in China, causing widespread panic among the expatriate community, which had to be withdrawn at this point: by the end of 1951, there were fewer than 1,000 British expatriates in China, and by 1954, the British-owned industries had basically withdrawn from the Chinese market.