In March 1989, the South Armagh Brigade of the Irish Republican Army (IRA) carried out a bold, meticulously planned ambush near the border, killing two senior officers of the Royal Ulster Constabulary (RUC). The attack became one of the most high-profile blows against British policing in the North during the final phase of the conflict known colloquially as ‘the Troubles’. “In the years that followed, claims emerged of Gardaí in the South tipping off the IRA – allegedly enabling republicans to prepare and execute the ambush.

The ambush was the culmination of an extended surveillance campaign lasting most of 1988 and 1989 by the IRA’s elite South Armagh unit, whose operations had long frustrated British forces along the heavily militarised border between North and South.

The RUC, whose reputation was shaped by decades of sectarianism and repression in support of the Unionist state, had long been a central target of Republican military operations. But the killing of Chief Superintendent Harry Breen and Superintendent Bob Buchanan marked a significant escalation — and a symbolic coup for the IRA.

The ambush came at a time when the British government was stepping up its war against the Republican movement in the North. It exposed even the most senior police figures’ vulnerability, delivering a humiliating blow to the RUC and its political masters.

The killings would also prompt the government in the South to establish the Smithwick Tribunal — a multi-million-pound investigation tasked with determining whether Gardaí colluded with the IRA by tipping off the South Armagh Brigade about the RUC officers’ movements.