As the leader of British Jewry’s main human rights group, Mia Hasenson-Gross regularly hears personal stories of loss, grief and helplessness.

But few encounters have affected Hasenson-Gross as profoundly as the one she had in 2019 with Rahima Mahmut, a UK-based activist for the rights of Uighurs, a Muslim minority that is the target of what the US State Department and many advocates say is an attempted genocide by the Chinese government.