British feared Somali union would unsettle Ethiopia and their East African colonies

Evidence

“Somalia: Attitude of the Tribes towards a Possible Union with the Somaliland Protectorate,” November 21, 1959, PREM 11/2582, UK National Archives. The British were concerned about not only Ethiopian reactions but also the effect that Somali independence might have on its East African possessions. — Abdi Ismail Samatar, Africa’s First Democrats, 1319