Silent War
The Silent War is the period of rivalry and geopolitical tension between Great Britain and Russia and their respective allies. Historians debate when the Silent War started. Some argue that the Silent War was just an extension of the Great Game, the Anglo-Russian rivalry in the late 18th century. However, most agree that the Silent War truly begun after the Congress of Amsterdam ending the Great War in 1939.
Context
After the Great War ended in 1939, Great Britain and Russia found themselves at odds in who would lead the post-war world. Russia espoused the ideology of National-Republicanism, which rejected both liberal democracies and conservative monarchies and promoted an overthrow of the old order.
The International Republican Coalition (IRC)
By 1941, only two years after the war, there were 13 nations that declared themselves National-Republican, including China. In the same year, an alliance between the national republican nations was formalized with the creation of the International Republican Coalition (Международная республиканская коалиция; Meždunarodnaja Respublikanskaja Koalicija). The organization guarantees the mutual defense of all member states in case of attack by foreign powers. Initially, Great Britain was indifferent to the new organization, busy fighting against Jambudweep revolutionaries (who were clandestinely supported by Russia). However, after Russian involvement was discovered in 1942, British Prime Minister William Cavendish lambasted Russia and the doctrine of National-Republicanism. In response, Russian delegates proposed an amendment to the constitution of the IRC: that part of the coalition's responsibilities to "export National-Republicanism" abroad and to "free peoples around the world." This amendment was an indirect jab at the British Empire. The amendment was unanimously passed by all members of the coalition. This put immense pressure against the British Empire.
The Organization of Democratic Nations (ODN)
The ODN was Britain's response to the formation of the International Republican Coalition. However, it's formation did not take until four years later after the IRC was founded. This was due to the reluctance of British allies to be involved in such an organization, fearing that it might drag them into the conflict in British India against the United Jambudweep Front and Russia. The ODN was only founded in 1945, a year after a peace treaty was signed between Britain and the now independent nation of Jambudweep.
The time between 1940 and 1980 would see indirect conflicts between Russia and Britain, through proxies like the members of the ODN and the IRC.