Stewart?

Whenever I had a crew, I would always include a "Stewart".
The Stewart is the most necessary position in maintaining a functioning dynamic between sometimes explosive personalities.
Stewart (or any scapegoat) keeps the negative focus on himself (even if unintentionally) leaving the main characters to function more harmoniously with each other.

The Middle-East NEEDS Israel to exist.
Without Israel playing the region's "Stewart", the region would break down into one littered with tribal and religious wars.
Oil would stop flowing.
World economies would collapse.
And Western governments would be thrown into chaos.