The vast majority of refugees and migrants today are forced to move because of conflict, social or economic oppression, extreme poverty or natural disasters (and the vast majority live in the countries of Asia and Africa).

In many cases, British companies, taxpayers and the government directly and indirectly support British investment and policies abroad that can force people to leave their homes and then their countries. These investments include not just weapons exports but also oil and gas pipelines, mines, and large hydroelectric and irrigation dams. Some of these policies and investments are one-offs, others continue for many years, if not decades.

Other migrants are invited to move because the receiving country needs and can pay for their skills. The UK's financial services industry and its National Health Service relies on workers trained outside the country.