What does the history of isolation have to say about the possible futures of exclusionary practices? Astronomical leaps in prison inmate counts across the Western world signal that democratic nations, particularly those with marked class stratification and low rates of citizen involvement in governance, find confinement a necessary and politically palatable strategy for dealing with criminals. The emergence of ‘truth in sentencing’ laws and the widening scope of mandatory imprisonment statutes have undermined the proportionality principle, consigning minor offenders to serve lengthy prison terms alongside violent criminals. The recent recourse to indeterminate sentencing of ‘dangerous offenders’ is also based on this justification of detention in which ‘prevention’ and ‘punishment’ become disturbingly unclear.1 What is ‘protective custody’ and what is ‘preventive detention’? The inseparability and the recurrent intertwining of ‘prevention’, ‘punishment’ and ‘protection’ reveals the historic connection between all of these state-endorsed practices in modernity, as well as between the populations rendered into ‘problems’. The persistence of these connections into the present day indicates the pressing political need to analyse confinement practices with respect to one another.