The country singer and fellow panelist Randy Jackson were caught in the middle when Mariah and Nicki had a furious bust up earlier this week, leading to auditions being cancelled for a day and sources close to Keith say he doesn't know what to do.
An insider told the Chicago Sun Times: ''Keith is such a wonderful, easygoing, lovely guy. This kind of drama was not the reason he signed on to be an 'Idol' judge. ... He hates nastiness in any form.''
During the fight Keith joked he felt like ''the UN [United Nations]'' caught in the middle.
Meanwhile, it has been revealed Mariah has hired extra security after claiming Nicki threatened to shoot her.
Mariah contacted chat show host Barbara Walters, who read out a statement on 'The View' which revealed several staff members had heard Nicki say: ''If I had a gun I would shoot the b***h.''
Barbara explained: ''She said she is very concerned, she's with her twins, she doesn't feel that anything would happen, but Nicki is unpredictable and Mariah says she can't take a chance and has hired extra security.
''Nicki has not apologised, but they were together in meetings... during which Nicki said, 'I love you, but we might fight again!'
''Mariah said at this point she doesn't feel comfortable emotionally but she will continue with the show because she loves mentoring the contestants.''
After having a music career that spanned five decades and saw the release of over...