If incarceration destroys your ties to the outside world, and builds only superficial ties to the prison world, how can prisoners be expected to suddenly switch

If incarceration destroys your ties to the outside world, and builds only superficial ties to the prison world, how can prisoners be expected to suddenly switch to being fully integrated members of society on release? Surely rehabilitation would be more effective if it concentrated on better integrating criminals with society rather than further alienating them? How could this be achieved without endangering people's safety?