Good Morning Francis,
Well, when we all forgive, reconciliation will follow. However, reconciliation between people is not always possible.
The key word there was “all”. If one party does not forgive, reconciliation will not occur.
Think of cases where i.e. someone is resentful toward a political leader. In that case, the leader may have offended the person without even knowing him. The person may eventually forgive the leader, but since there was no relationship in the first place, reconciliation is more of something that occurs within the individual than an actual interaction with the leader. This is also applicable when I forgive a terrorist who has caused harm far away, when I forgive someone who died long ago, and many other instances.
There is a holiness attained. Right relations is a holiness, and it is wonderful. But you see, when we resent someone we do not know, that restoration is something that simply happens within the person. We let go of our resentment. This is not about a personal relationship with someone else, it has more to do with a state of mind, a state of holiness within. It is about our personal relationship with God. If we cannot forgive someone, we will not realize God’s forgiveness.
Ye of little faith!

Yes, sometimes I get pessimistic too.
Yes, when all else fails… not that we should be standing around thinking about options while people are dying.
Yes! But as bricks, we are called to take on His work, God does the healing, but we have to be His tools. Forgiveness heals. Again, we are talking about long term solutions that can begin in the short term - with a change of heart.