Most western countries don't even call them Christian states. And even they might have issue if I start propagating a religion which attacks and mocks religious figures of Christians. There might be more sects in Malaysia but Shiaism might be the most different sect from other sects present in Malaysia. At best most sects would have difference on folding of hands during Namaz. The problem with Shiaism is that propagating it means you are prorogation hatred against those personalities which are reverted unanimously among the sunnis. Other sects don't face this issue. They don't propagate hatred against religious personalities. Unfortunately this isn't the case with Shias, What if tomorrow Shia preacher promotes something against the first 3 caliphs. What if the local population is infuriated by that. Who would be responsible then? If shiaism promotion was limited to just differences between performing namaz and other such trivial issues, things would have been completely different. About the bold part, Pakistan itself is the biggest example. Before Iranian revolution of Khomeni despite sectarian differences, there were not much violence. After iran started to meddle inside Pakistan and started propagating Shiaism, situation started to deteriorate from there. Saudis started to fund Madarsas to counter this trend and hence the bloodshed and extremism started in Pakistan. It might be interesting for you but most books written in Pakistan based on promoting Shiaism were written after the Iranian revolution. If Pakistan would have stopped both Iran and Saudia to meddle in its country, situation would have been much better.