Heavier-than-expected Security

The "dissident" faction of the Provisional IRA ("Provos") in Northern Ireland has not gone along with the peace agreement, and has been functionally blacklisted by the mainstream Catholic-aligned parties for their intransigence... and continued attempts at terrorism.

Thankfully, the police and the British Army are still on the job:

IRA dissidents telephoned in at least two warnings describing the bomb's approximate location — raising police fears they were being lured into an ambush, a past IRA ploy. But the dissidents said in a later statement they abandoned the car bomb short of their intended target, a major army base in nearby Ballykinlar, after encountering heavier-than-expected British security near the installation.

This makes it a clean sweep since the 1998 Omagh bombing; not one of the many car bombs constructed since then by the dissident IRA has reached its target.