There are few more fraught political issues than migration, given that civil conflict, political unrest and climate change translate into increasing numbers of people forced to flee their homes. The war in Sudan seems likely to result in more refugees seeking to cross the Mediterranean to Europe and to seek asylum in neighbouring countries. Already more than 100,000 people cross the Mediterranean from Africa to Italy each year – 181,000 in 2016. Some flee war; some, understandably, wish to better their lives. And there is, of course, a corresponding problem in the US from migrants seeking to cross the border from countries such as Venezuela.