Few will argue with the statement of Strathclyde Police that whoever sent parcel bombs to the Celtic Football Club manager Neil Lennon and two other figures associated with the club is guilty of a despicable and cowardly act.
Football in Glasgow has for decades generated an unhealthy level of passion and confrontation. It continues to do so to a worrying extent: in February more than 200 arrests were made following a Celtic-Rangers match. But sending letter-bombs is on another level. It is terrorism. They are meant to cause serious injury or worse; at the very least they are intended to intimidate individuals and their families. Bullets previously sent to Neil Lennon were posted from Northern Ireland, where both loyalist and republican groups learnt how to construct these potentially lethal devices.
It is highly unlikely, however, that any organised group on either side of the Irish Sea has been behind this or the earlier incidents designed to torment the Celtic manager. The probability is that they have been the work of a single oaf, or perhaps two or three oafs, who think football is a form of warfare rather than sport. The hope is that sooner rather than later police will catch up with them.
While police investigations are under way the authorities are already making commendable efforts to gain more control over what, in Glasgow at least, sometimes brings national shame to the national game. There has been disorder on and off the field, involving not just unruly fans but also on occasion players and managers. But there are also deep underlying issues including sectarianism, serious drunkenness and social problems.
Police calculate that there is a 170 per cent rise in the usual level of violent offences when Old Firm matches are played. And, sadly, the amount of violence in the home more than doubles at those times. Efforts to tackle all this led last month to a summit attended by the clubs, the police and the authorities. This produced a programme for greater police co-ordination, stricter enforcement of anti-sectarianism and drink-related laws. This is a promising start, but it will take a sustained effort to disinfect this toxic subculture.