Those who still support the use of violence in the pursuit of any cause in Ireland should carefully consider all the circumstances surrounding the appalling murder of Thomas Niedermayer.
As we reported last week, a new book sets out how Mr Niedermayer, the German-born managing director of the Grundig electronics plant in the Dunmurry area of Belfast, was abducted at the height of the Troubles in 1973
There were many terrible stories on all sides during that period, but the devastating consequences for one innocent family who moved to start a new life in Ireland were almost beyond belief.
While every killing over the last five decades and beyond was cruel and wrong, there was something particularly dreadful about the deliberate targeting of a respected foreign national who had no possible connection with any group here.
The IRA decided to seize Mr Niedermayer (45) and hold him hostage in an attempt to secure freedom for two of its members, Marion and Dolours Price, who had been jailed for their involvement in a London bombing campaign.
His wife, Ingeborg, emotionally appealed for his release after the kidnapping, which was witnessed by his traumatised teenaged daughters, Renata and Gabrielle, but the IRA callously remained silent.
Although it later transpired that Mr Niedermayer had been killed within days of his disappearance, possibly while attempting to escape, his body was not found for another seven years, hidden in a rubbish dump at Colin Glen forest park just a few hundred yards from his home.
Mrs Niedermayer eventually returned to Germany, but in 1990 she flew back to Ireland, booked into a hotel in Co Wicklow and took her own life by walking into the sea. Renata and Gabrielle also died by suicide in subsequent years, as did Gabrielle's husband.
These are not matters which can be regarded as consigned to our distant history, as both republican and loyalist paramilitary organisations have been responsible for murders and attempted murders in recent months.
They need to reflect on the Niedermayer tragedy and tell us if they can justify inflicting the same level of grief on any other family. The answer should be clear.