当事者

An essential condition for a helpful interview is a quiet room in which doctor and parents can sit comfortably and in private without being interrupted

There should be more communication between the persons concerned

You speak pretty highly of him but you're directly involved. I think my less charitable view might be more accurate since I can look at things objectively

The inhabitants rebelled against the ruler

He mediated between the two parties

Two different parties with common interests were on the warpath when he cut in to settle the dispute

You wouldn't be so casual about it if you were directly involved

This agreement is binding on all parties