<While they're at it, I hope people are just as concerned about the Protestant militia groups. They've proven just as deadly as the IRA over the years.

Well that all depends on whether you read biased American papers or biased British papers ;-)

The IRA disarmament is the most crucial to the process - they are much larger than all other groups combined. The UVF, UDA etc have all but disappeared from the landscape.
If the IRA goes away, then the Protestant forces have no reason for existence and thus no support. They too will wither and die.

There will of course be fanatics, thugs and idiots on both sides who want to keep it going to support their cause/drug dealing/extortion/sadistic tendencies.