A timeline, in which the post-WW2 history is much more favorable to the United Kingdom, allowing it to stay a stronger world power in spite of countries like the US and the USSR overshadowing the UK.
The United States successfully test and later use their newly developed nuclear weapons, a new strategic weapon that could turn the tides of world power. British and Canadian scientists worked on the Manhattan Project in exchange for a promise from the US government that Canada and the UK would receive all data and documentation about the technology. However, shortly after the successful tests and deployment of the weapons, President Truman denies the British and Canadian governments all promised information. Angered by this apparent violation of their deal, the UK gathers their Manhattan nuclear scientists to start their own program and invites Canada to join, an offer which Canada gladly accepts. Australia, New Zealand and South Africa join the program a few months afterwards. This joint development program marks the beginning of a very important partnership.
King George VI visits the Union of South Africa. A bit shocked by the segregation policy there (he was only allowed to shake hands with whites and was followed by secret police, whom he called ''the Gestapo''), the King approaches the then Prime Minister of the Union, Field Marshal Jan Smuts, a well-known pro-British Afrikaner politician during the visit and explains his view on the situation in private. General Smuts reveals that he is in favor of gradual integration of all racial groups in South Africa, a turn from his previous views, however the future of this endeavor will depend on the results of the 1948 general election.
The general election in the Union of South Africa is narrowly won by the United Party of Jan Smuts, who is once again sworn in as the Prime Minister. His government promises a program of gradual racial integration, a move which pleases the majority of the blacks and coloureds but is quite unpopular with the Afrikaners and the main opposition party - the National Party.
A Communist victory in the Chinese Civil War is imminent. A Royal Navy vessel is attacked by Communist forces. After a consultation with its Commonwealth allies, the UK takes up a more pro-Nationalist stance and refuses to recognize the newly established People's Republic of China as do Canada, Australia and other UK allies. The Hong Kong garrison is strengthened and the UK continues to recognize the Taiwan-exiled Republic of China as the legitimate representative of China.
The UK and its allies form part of the UN coalition fighting the Communist forces in Korea. While the PRC enters the war on North Korea's side, Hong Kong remains untouched by the war despite Britain's fears. This is mainly due to strong US and UK military presence in the Taiwan Strait and the fact that Hong Kong was apparently deemed more useful to the PRC as a British territory for the time being.
The health of Marshal Smuts worsens and he resigns as Prime Minister after completing the first part of his racial integration program. Smuts retires to his farm in Transvaal and J.G.N. Strauss takes over as Prime Minister and leader of the United Party, determined to continue in Smuts' work and being advised by him from his retirement.
The division between the population of South Africa deepens as various militant groups emerge both from the Afrikaner far-right, demanding a stop to the integration efforts of the government, and from the African far-left, supported by the Communist bloc, claiming the government's efforts are too little, too late. Violence gradually increases to the point when it's possible to talk about a full-fledged civil war. The South African military fight the various rebel groups, however, the situation is getting out of hand. The government requests UK military assistance. Troops from the UK, Canada, Australia and New Zealand deploy to South Africa to help restore order in the country.
Winston Churchill's government engages in negotiations with the ROC which is still the legitimate representative of China as recognized by the UK. In exchange for economic and military assistance to the Taiwan-exiled government, the Imperial China-era 1898 Second Peking Convention is later amended and modifies the 99-year lease for the Hong Kong New Territories to a permanent cession of the territory to the United Kingdom (the British convince Chiang Kai-shek that Hong Kong is better in British than Communist hands).
The Egyptian government unilaterally abrogates the 1936 Anglo-Egyptian Treaty which gave Britain control of the Suez base. Britain, however, refuses to withdraw, relying on her treaty rights and the garrison strength.
The joint Commonwealth nuclear program finally comes to fruition as the first British nuclear device is detonated in Western Australia during Operation Hurricane. The cooperation between the UK, Canada, Australia, New Zealand and South Africa becomes official with the creation of the Commonwealth Defense Alliance, providing mutual defense and military cooperation to its members.
In the wake of the 1952 Egyptian coup, the UK tries to re-approach Egypt and negotiate a settlement to the strained relations of the two countries.
The Egyptian-British negotiations are successful and an agreement is reached. Britain will terminate their rule in Sudan and Sudan will be granted independence by 1956. Furthermore, Britain will help finance the Aswan Dam, provide further economic assistance to Egypt and withdraw their troops from Suez in exchange for continued ownership of the Suez Canal by the British-French Suez Canal Company until 1968, when it shall revert to the Egyptian state. Egypt also guarantees international access to the canal without any discrimination. During the negotiations, the British make it clear to the Egyptians that in case the agreement is broken, they will not shy away from using military force to retake the canal and they trick Nasser into believing that in that case they have support of the United States.
As the situation finally calms in South Africa, the government forces assisted by their Commonwealth allies have the upper hand. An agreement along with a new constitution is drafted. The government will continue with their reforms and all racial groups shall be gradually equalized within South Africa with fully democratic non-discriminatory political representation being established. As a compromise towards the conservative, mainly-Afrikaner groups, the current national flag with its primarily Afrikaner symbolism is kept and with the new constitution, the country is federated, allowing further autonomy to the four provinces. Prince Edward Islands become a federal territory. The fate of the South-West Africa mandate is not yet decided and it remains under South African control.
Although Britain is no longer the strongest world power by far and is overshadowed by the US and the USSR, it is still considered a very influential country in the world and an important great power.
Britain develops the Blue Streak ICBM to replace the V-bomber force as main nuclear deterrent. To protect the missiles from enemy first strike, underground silos are envisioned, a concept which would be exported to the US. The missiles are tested in Woomera Missile Range in South Australia. However, the cost of the project rises and influential politicians lobby for its cancellation. Lord Mountbatten argues for sea-based nuclear deterrent. On the other hand, the British Army and Australia lobby for continuation of the project. Eventually, the project goes ahead but the number of silos and missiles built is significantly reduced. A few silos are built in Britain and two are built in Australia.
As the British-Commonwealth nuclear program matures (including the first thermonuclear tests), a nuclear sharing program is initiated by Britain for its Commonwealth allies which gives them control of British-owned nuclear weapons as a compensation for their help in Britain's nuclear efforts. The weapons remain British-owned to avoid international complications, similar to the later sharing of American nuclear weapons by NATO members. They are also given full documentation on the nuclear projects.
Britain, the Federation of Malaya and their Commonwealth allies achieve a victory in the 12-year long Malayan Emergency, defeating the Communist guerrillas.
Cyprus gains independence from the United Kingdom, with Britain retaining the Sovereign Base Areas of Akrotiri and Dhekelia under special terms. The bases become the new British centre for military activity in the Near East after troops were withdrawn from Suez.
Almost all of the major British colonies are decolonized and most of them become republics within the Commonwealth, following India's example. Others, however, choose to retain the monarchy and the number of Commonwealth realms increases with the addition of countries like Jamaica, Barbados or Malta.
Violence appears in Northern Ireland between the republicans and the loyalists as several paramilitary organizations on both sides launch armed campaigns. British security forces attempt to restore order but their success is limited.
As Britain continues successfully with the development of domestic nuclear submarines and related technologies, namely the HMS Dreadnought, followed by the Valiant-class, the focus of Britain's nuclear deterrent changes to developing submarine launched ballistic missiles and nuclear submarines to carry them. This project gains political support and replaces the Blue Streak land-based missiles and the V-force as Britain's primary deterrent, while retaining the other options in a limited way to preserve a nuclear triad. This program concludes with the comissioning of the Resolution-class nuclear submarines armed with British ballistic missiles with nuclear warheads.
Britain also engages in development of space technologies. The UK joins forces with Canada, Australia, New Zealand and South Africa to develop Black Arrow, a light satellite carrier rocket. Woomera Missile Range in South Australia becomes the new Commonwealth spaceport.
Britain cooperates with Malaysia and Brunei in quelling the Brunei Revolt, defeating the Indonesian-supported rebels. This further strengthens Britain's friendly ties with those two countries.
British, Commonwealth, Brunei and Malaysian forces are victorious in the three year long Indonesia-Malaysia confrontation, after which a normalisation of relations between Malaysia and Indonesia begins.
Despite strained relations and numerous tense points, the agreement with Egypt holds and in 1968 control of the Suez Company is given to the Egyptian state as planned, after Britain and France contribute to repairs of the canal after the 1967 War with Israel. The canal would remain closed until 1975, however.
The first successful flight of the Black Arrow takes place in, placing the Prospero satellite in orbit. The Black Arrow rocket would continue to be used for both military and civilian space projects of the five Commonwealth countries that participated in its development.
The Third Cod War, pitting against each other the marine resource interests of the UK and Iceland, ends with negotiations reaching a compromise in drafting the Icelandic EEZ. During the third of the Cod Wars, several rammings, net cuttings and warning shot incidents occurred.
The UK joins the European Space Agency and the Ariane rocket programme (after the failure of the previous Europa programme, using elements from Blue Streak), intending to cancel the Black Arrow program. This, however, faces significant opposition from Britain's Commonwealth partners who prefer to have their independent access to space via Black Arrow. Britain eventually agrees to continue to participate in both programmes after the Commonwealth partners promise to increase their financial participation in the Black Arrow programme. Canada later becomes an associate member of ESA in 1979.
Argentina launches a surprise invasion of the Falklands in order to raise the popularity of the ruling Junta. Counting on Britain not responding militarily, the Argentines take the islands despite the resistance of the small British Marine presence. The British Prime Minister, Margaret Thatcher, however decides for a military action when all attempts for a diplomatic solution acceptable to the British fail. A large task force sets sail, joined by several Canadian and Australian ships. After the allies take control of the sea and air around the islands, including the sinking of the Argentine cruiser General Belgrano by HMS Conqueror, troops mainly from the UK but also some special units from Canada, Australia and New Zealand, perform an amphibious landing. South Africa provides medical and other support, including a refueling tanker without directly sending in combat troops. The Falklands are retaken and the British military receives an influx of praise as well as funds. Thatcher manages to restore world's confidence in Britain continuing to be a major world power.
In the wake of the end of the Cold War, the last land-based nuclear ballistic missiles of the UK are decommissioned (as in France), while Britain keeps the submarine- and air-based components of her nuclear deterrent. The Commonwealth nuclear sharing continues as well, to some extent.
Britain, along with other allies, participates in the Gulf War and NATO operations in former Yugoslavia.
A civil war has been raging in Sierra Leone, a former Commonwealth realm, since 1991. In 2000, Britain engages in a military operation to first allow foreign nationals to leave the country, since rebel troops are approaching Freetown, the capital. After that objective has been completed, the British assist UN and Sierra Leonese troops in fighting the rebels and perform a highly successful hostage rescue operation. The British intervention receives high praise from the international community and the pro-British sentiment in Sierra Leone is very strong, with Tony Blair being considered a national hero. British troops remain in Sierra Leone to assist in training the local military.
Sierra Leone becomes the first country to restore a monarchical system of government in the 21st century as a referendum results in a majority of voters showing support for restoring Sierra Leone's former status as a Commonwealth realm. Observers note that this is mainly due to the highly praised intervention of the British in the civil war, without which, the war would probably still be ongoing. Sierra Leonese President Ahmad Kabbah, who said that ''the Sierra Leonean people will never forget the British help'', becomes an executive Prime Minister with Elizabeth II restored as Queen of Sierra Leone, a post she last occupied in 1971.
Under Tony Blair's premiership, Britain participates in the Iraq and Afghanistan Wars together with the US.
Britain takes part in the UN-sanctioned intervention in Libya and joins the coalition supporting the fight against the Islamic State. Britain also engages in humanitarian efforts against Ebola in Western Africa, including Sierra Leone.