Yesterday's decision by Neil Lennon, the Glasgow Celtic midfielder, to withdraw from international football after a death-threat, sends a grim message which goes far beyond the world of sport.
It illustrates more graphically than any politician's pleas or any newspaper's editorials, the corrosive nature of the sectarianism and racism that infects Northern Ireland.
The world increasingly turns to sport to express the common humanity of its many peoples. And of all sports, football is the most universal, a shared human experience across all continents and nations, north or south, rich or poor. Yet in Northern Ireland, it is part of the calculus of sectarianism. Five weeks ago a 19- year-old Catholic youth was picked for murder on the streets of Belfast because he wore a green Celtic shirt.
Neither Neil Lennon's outstanding sporting talent nor his courage in crossing sectarian lines in the interest of the game put him beyond the reach of the bigots. In Windsor Park 18 months ago he was heckled by Loyalists after a game with Norway. Death threats appeared on walls in his native Lurgan. The latest threat - purportedly from the Loyalist Volunteer Force - was too much. He is entitled to live his life without fear for his family and for himself.
The LVF has denied it issued the threat. Some commentators feel that in these circumstances, Neil Lennon might reconsider his decision. His many fans would undoubtedly hope that this could be so. Lovers of sport may feel his decision plays too readily into the hands of the extremists and the wreckers. But he and he alone can take the decision.
This depressing and appalling episode is unique only in that Neil Lennon is a public personality. Thousands of people are obliged to live daily and nightly in the shadow of sectarian hatreds and threats. Many - like Neil Lennon - simply give up and move on. Even police officers and their families have had to be relocated and rehoused in large numbers.
Is this to be the reality of life in Northern Ireland for the indefinite future? Only the recklessly optimistic will believe it can change quickly. But it is certain that it will not change at all if there is a collapse of the political processes and institutions set up under the Belfast Agreement and if Northern Ireland does not have an effective police service, acceptable to and supported by both sides of the community. Neil Lennon's loss to the world of sport should be a signal lesson, a frightening indicator of what unchecked sectarianism will bring into daily life.