mediate between

mediate between

To act as an intermediary negotiator between two or more people, groups, companies, countries, etc. The neutral country volunteered to mediate between the two warring nations to broker a peace treaty that would benefit both sides. Children shouldn't have to mediate between their parents—that is an unreasonable and unhealthy burden to place on them.
See also: between
Farlex Dictionary of Idioms.

mediate between (someone and someone else)

to negotiate an agreement between people. I will have to mediate between Mary and Vernon. No one wants to mediate between them.
See also: between
McGraw-Hill Dictionary of American Idioms and Phrasal Verbs.
See also:
  • arbitrate
  • arbitrate between
  • (Someone or something) called, they want their (something) back!
  • tomorrow
  • be greater/more than the sum of its parts
  • one rotten apple spoils the (whole) barrel
  • one rotten apple spoils the (whole) bushel
  • a bad apple spoils the (whole) barrel
  • a rotten apple spoils the (whole) barrel
  • a rotten apple spoils the (whole) bunch
References in classic literature
The mixed constitution is practicable in a state where the middle class is strong, as only the middle class can mediate between the rich and the poor.
In the case of dead matter, however, such phenomena are less frequent and important than in the case of living organisms, and it is far less difficult to invent satisfactory hypotheses as to the microscopic changes of structure which mediate between the past occurrence and the present changed response.
As I felt bound to assist him in this, and also to mediate between them; with the view of sparing the mother's feelings as much as possible, I wrote to her that night.
When asked by mediamen, on the sidelines of the Group of 7 meeting in Biarritz, France, whether his offer to mediate between the two countries was still on the table, the US president replied, "I am here.
Earlier during PM Imran Khan visit to US, President Trump had offered to mediate between the two countries on Kashmir conundrum.
WASHINGTON -- US President Donald Trump on Monday expressed his willingness to mediate between India and Pakistan to resolve the 70-year-old Kashmir dispute if both the neighbouring countries asked him for it.
Manama: Bahrain's foreign minister has denied reports that he had requested Algeria to mediate between his country and Iran.
"A brother does not mediate between his brother and a foreigner," Shaikh Khalid Bin Ahmad Al Khalifa was quoted as saying when he was asked about the tension between Bahrain and Iran and the chances of Manama requesting Algiers to mediate with Tehran.
Summary: Turkey is prepared to mediate between Israel and Syria if the two agree to resume stalled indirect talks
Turkey is prepared to mediate between Israel and Syria if the two agree to resume stalled indirect talks, Prime Minister Recep Tayyip Erdogan was quoted as saying Friday.
Sue would explore how she could mediate between being a divorce mediator and being a divorce arbitrator.
This interval, in fact, enables Brent to mediate between a number of oppositions at the same time.
In the interpretation of Scripture, allegory and tropology (the moral sense) mediate between the letter and the spirit.
They mediate between their rural, semi-proletarian families and capitalist factories.
NEW YORK -- UN Secretary General Antonio Guterres has renewed offer to mediate between Pakistan and India to de-escalate tension between the two countries.