Short answers, pulled from the story.
The United Nations High Commissioner for Refugees published an estimation of 4.4 million people worldwide as either stateless or of undetermined nationality in 2022.
Conflicting nationality laws such as right of soil and right of blood create stateless births when a child is born in a state that does not recognize jus soli while neither parent can transmit nationality by jus sanguinis.
The United Nations adopted the Convention relating to the Status of Stateless Persons in 1954 to provide a framework for the protection of stateless people.
Kuwait has the largest stateless population in the entire region and revoked the citizenship of 42,000 people in just six months during 2024.
The United Nations Children's Fund estimated in 2013 that 230 million children under the age of 5 have not been registered.