Dealing with enemy aliens in WWI: security versus civil liberties and property rights

WWI is probably the first conflict in which governments and armies have dealt with the issue of civilian of enemy nationalities on a massive scale. Governments and parliaments discriminated between citizens and aliens and established an equation between nationality/ethnic origins and dangerousness, citizens of enemy nationality and citizens of enemy ethnic origin were lumped together and stripped of their liberties, rights and properties. This article tries to understand how the belligerent countries addressed the enemy aliens issue and explores the historical roots of a widespread twentieth-century practice.