They can in some countries. China for example. America has de facto exile due to the No Fly List: https://www.theguardian.com/commentisfree/cifamerica/2010/ju

They can in some countries. China for example. America has de facto exile due to the No Fly List: https://www.theguardian.com/commentisfree/cifamerica/2010/jun/17/no-fly-list-american-muslim-egypt https://www.theguardian.com/commentisfree/cifamerica/2010/ju... https://www.aljazeera.com/indepth/opinion/2013/02/201324165957645514.html https://www.aljazeera.com/indepth/opinion/2013/02/2013241659... https://www.thedailybeast.com/one-womans-case-proves-its-basically-impossible-to-get-off-the-no-fly-list https://www.thedailybeast.com/one-womans-case-proves-its-bas... https://www.courthousenews.com/en-banc-9th-circuit-takes-up-fee-challenge-in-no-fly-list-fiasco/ https://www.courthousenews.com/en-banc-9th-circuit-takes-up-... https://foreignpolicy.com/2018/05/01/who-can-challenge-the-no-fly-list https://foreignpolicy.com/2018/05/01/who-can-challenge-the-n... Snowden is arguably in exile, as his passport was cancelled, but he wouldn't be refused entry :-)