Sunni - Shia war. As much as I hate seeing Bahrain getting destroyed in this process (it’s a lovely country and it has a great deal of history — Bahrain was called Dilmun and was on the trade routes between the Sumerians in what is now Iraq and the Indian Harrappan civilisation and has its first mention in 3000 BC — it is also the supposed site of the garden of Eden (not so outlandish if you consider that the water levels would have been lower and the Persian gulf a stream), I think it’s a good thing we should encourage.
Trust you to know about Bahrain’s glory in antiquity.
On a more recent note, the British Empire succeeded in getting the decrepit Persian Empire to turn control of Bahrain over to British proxies, the current ruling family, sometime around 1780 or so.
The Persians still consider it theirs and now that the Shias have got their dander up, expect a low boil for a long time.
Still, shows how exasperated the Saudis with Obama that they actually sent their own troops and organized others, sovereign and private to assist Bahrain.
Rooting for the Saudis ain’t too odd now, since in Libya we’re kinda helping hardcore jihadis! :>>