evidence: For longer than a year, gardai have been grappling with the challenge of managing migrant flows across the border from Northern Ireland. In an intricate dance of enforcement and political diplomacy, they have been running "shadow operations" in the region, trying to make their presence felt while remaining invisible. It is proving an impossible task. Each week, when time and manpower permit, detectives from the Garda National Immigration Bureau travel from the capital to Louth, where they set up checkpoints on the M1 to stop cars, minibuses and coaches that might be transporting