Obviously the more friendly countries in the Middle East aren't mentioned here: Oman, UAE, Qatar, because they aren't involved in any conflicts or political standoffs.
Oman, Saudi Arabia and Qatar are only friendly because they have done religious cleansing 30-50 years ago (all three used to have significant Shi'a populations, Saudi Arabia still has some), and back then nobody was watching. So not that much is really known about those events. Currently, yes, they are mostly peaceful.
Bahrain and UAE are peaceful, but certainly have political standoffs that could explode.
Bahrain smashed their Shia rebellions during arab spring with tanks, but that was blessed by USA as opposed to the attempted smashing by Syria and Lybia of their own rebellions.
With Saudi Arabian provided mercenary tanks (because Bahrain's own army is at least partly Shi'a), and this was definitely not "blessed" by the USA. Tolerated, maybe, in the sense that the US was not going to create a shooting war with Saudi Arabia to stop this, yes.
Don't oversimplify it. The USA is constantly pressuring Bahrain into allowing the Shi'a a voice in government, and every 6 months or so, Bahrain expels yet another American diplomat for mentioning the Shi'a.
A big problem here is that Iraq is so factionalised that you can't easily categorise it. The chart doesn't break out Iraq and Kurdistan, yet the Kurdish controlled areas are effectively a separate country. So which group's political affiliations do you use when drawing up the chart?
