AFAIU certain Shia practices are objectionable to strict Salafis as alleged forms of heresy/idolatry, which might be one of the reasons for Saudi government’s dislike for their Shia minority. Now, how about vice versa? Let’s say if Iran in the future takes over areas with lots of Sunni people, will the ruling Iranian Shia see any of Sunni beliefs or practices as heretical and worthy of suppression? Or will they just see the Sunni as ok Muslims who are not practicing the religion as well as they should be, but not doing anything wrong or objectionable either?
Shi‘ah have a grudge about ancient and present persecutions by Sunnis. Shi‘ah feel put upon and oppressed. Their antagonism to Sunnis on specifically religious grounds is that the first 3 caliphs, followed by the Umayyads, didn’t do right by ‘Ali and his family. So their main problem with Sunnis is resentment about being treated unjustly by them. It was a family struggle between the ‘Alids and the Umayyads, who were literally cousins, two families belonging to the same clan.
Sunnis focus more on doctrinal heresy that they impute to the Shi‘ah. While the Shi‘ah for their part, for all their passionate investment in their doctrine, use “they done us wrong” as their main anti-Sunni argument. The two sides are talking past each other and don’t really connect or communicate very well with each other on the issues of their antagonism.
In general, though, they’re perfectly capable of setting those issues aside and working together, when the focus is on the Islam they share in common, as long as they can stay off the topic of who’s right and who’s wrong in their family dispute. But there are minority hardline groups (who are pretty much all on the Sunni side and who refuse to give any Shi‘ah people the time of day, ever), because in their hardline mindset the charge of heresy trumps everything else. I get the sense that the Shi‘ah are more willing to drop the antagonism if only they can get an apology and an admission from Sunnis that they done them wrong. While the Sunni hardliners’ emphasis on heresy means they cannot accept the existence of the Shi‘ah as a doctrinal group at all and just want them to not exist.
But don’t forget the ethnic component. Many times the Sunni/Shi’a divide also follows ethnic lines. The classic is Sunni Arab versus Shia Persian, but others exist. Those can also hold grudges which can be semi-related to the religious divide as well.
Can you give other inter-ethnic examples of Shi‘i versus Sunni? I don’t think there are any. For the Shi‘i populations of Lebanon, Syria, Yemen, Iraq, Bahrain, Afghanistan, Pakistan, and India, the Sunni-Shi‘i divide is intramural, intra-ethnic. The only other ethnically sectarian divide that might exist would be internal to Pakistan, where a few northern ethnic groups like Hunza and Balti belong to the Isma‘ili sect. Iran itself was majority Sunni until the 17th century.
During Iran’s antagonisms with Sunni powers in the 1980s, historical Arab-Persian ethnic sentiments did get added to the Sunni-Shi‘i conflict, as you said. But the ethnic issues of Arab versus Persian are really an independent story from Shi‘i versus Sunni. They coincided during the 1980s under Khomeini, but otherwise they haven’t been historically linked. There was some Sunni-Shi‘i conflict involved when the Ottoman Empire attacked Safavid Persia. But specifically Arab Sunni on Persian Shi‘i is not a historical conflict apart from the 1980s. Historically you had both Sunnis and Shi‘ah in both the Arab world and Persia.
The rise of the ‘Abbasid dynasty and their overthrow of the Umayyads in the 8th century was fueled in large part by Arab-Persian ethnic sentiment. In those days, about 120 years after Muhammad, the original Meccan clan structure was still extant. The ‘Abbasids were another family from the same clan as the ‘Alids and Umayyads. They were literally cousins fighting each other. The ‘Abbasids gained their power base from eastern Iran (majority Sunni at the time). The ‘Alids and their Shi‘ah party (based in Iraq) also allied with the ‘Abbasids to overthrow their enemies the Umayyads.
In a broad sense, the Umayyads stood for Arab ethnicity, and the ‘Abbasids stood for Persian resentment of ethnic inequalities under the Umayyads. However, the ‘Abbasids were still Sunni, and as soon as they were in power, they turned around and started persecuting their erstwhile Shi‘i allies.
I think you’re overestimating the historical differences for the divide and underestimating the doctrinal differences.
The historical issue of whether Ali should have been the first or fourth successor to Muhammad is a pretty moot point in the 21st century. If that was all there was to the argument, it would be as relevant as the Guelphs and the Ghibellines.
The doctrinal issue, on the other hand, is still relevant. Do Imams have a special authority over religious doctrine or don’t they? That’s the real issue that keeps the divide alive.
It depends where you are. The Far East has no Shias; while in the Mid East Shia/Sunni divide is massive. In Iraq before the US’s little party; there was a large amount in intermixing and intermarriage between Shia and Sunni’s and this remains the case in Pakistan and India;although secretarian strife is regrettably growing.
A Pakistani who dislikes Asif Zardari dislikes him because he is corrupt an idiot and has a horrid mustache. the Saudis dislike him because he is Shia.