Internal displacement has become one of the most pressing geo-political concerns of the twenty-first century. There are currently over 45 million internally displaced people worldwide due to conflict, state collapse and natural disaster in such high profile cases as Syria, Yemen and Iraq. To tackle such vast human suffering, in the last twenty years a global United Nations regime has emerged that seeks to replicate the long-established regime of refugee protection by applying international law and humanitarian assistance to citizens within their own borders. This book looks at the origins, structure and impact of this new UN regime and whether it is fit for purpose.