THIS year — June 26 — marked the 20th anniversary of the murder of Veronica Guerin by drug criminals. Five years later, in September 2001, another journalist, Martin O’Hagan, was murdered by the Loyalist Volunteer Force. He was the only journalist to be killed in Northern Ireland’s 30 years of tit-for-tat terror, which, compared with the fate of journalists in many of the world’s conflict zones, is pretty remarkable.