Actually having thought about it a little, I've decided to completely end the Salutariat, but over an extended period of time.
Unfortunately, the New Circles were unable to hold together the growing nationalisms in the diverse states. While from the 30s to the 60s, a degree of homogenisation had set in as Indians mixed with Africans and Europeans, after the 1960s and as internal migration quietened down, cultural heteroginisation set in.
The first sign of a final break down in the already weakened Salutariat was in East Africa. The Arab-African peoples of the Zanzibar Coast had always resented the conquest from the interior by New Zion. As the coast became home to their own independent fleets, the economy of the region shifted from the interior to the coast. Riots broke out, as the costs of maintaining India fell increasingly on the heads of the Zionese.
A similar process was also happening in Australia. While the Australians were well mixed along the internal borders, the country was essentially divided in two, with Indians and Africans in the West and Europeans, Pacific Islanders and Chinese in the East. The interior was dominated by a mixed Arab-Irish-Indian-Aborigine people of camel and horse herders known as the Bedouin. It wasn't long before the more populous east and the mineral-rich west were at each others throats. And the Bedouin wanted to be separate from both. There were divisions over foreign policy too. The West wanted to build a close relationship with East Africa and pour millions into rebuilding India. The East wanted a constructive relationship with Aotorie and Japan, and concentrate on their own affairs.
There were less divisions between Britain and the Caribbean, as they had become well integrated during the height of the Salutariat. But increasingly, 'Core Britain' wanted out of the fractious situation in Australia, India and East Africa.
In 1986, things came to a head. The weak Salutariat government was officially dissolved, and borders fixed for a whole series of new states. The Bedouin sided with the Easterners, and founded the Republic of Australia. The Westerners created a confederacy, and invited those who had fled during the Revolution back home. East Africa was divided into the republics of New Zion and Zanzibar. India was divided between the irradiated parts under the governance of the League of Nations, a mostly Muslim Northeast, a Tamel-Sinhalese Republic of Greater Ceylon, and two Peninsular Indian states.
In Britain, the Salutariat was officially abolished the United Republics of New Britain was inaugurated. Having inherited a large navy, and the strategic position of ports in the Atlantic, Britain may no longer be a first rate power but for now, its legacy was secure, and it was economically stable enough to rebuild itself.