>>>I suspect that one plausible answer lies in the way the UK dealt with the IRA's methods- merciless, ruthless pursuit and vigilance, but invading Ireland was never a serious thought.
>
>Of course it wasn't any sort of vigilance that took down the IRA.

Good analysis of what happened.

However, while waiting for it to happen the UK endured some serious attacks. I think we should look at how they responded.