>Dealing with foreign beliefs and prejudices is part and parcel of having an immigration system.

It is inevitable. That does not mean that we can, or should, tolerate all such examples indefinitely.

>Sometimes these American soil conflicts spill back out onto the motherland countries in a big way, as Cuba, Ireland, and Israel/Palestine can all attest.

I am well aware. But all those conflicts occur "back home". Boston Irish support for the Nationalists in Ireland may not have been a wonderful thing to other Americans, but at least Americans did not have to deal with the conflicts on their own soil. Miami anti-Castro Cubans did not fight Miami Cuban Communists on American soil.

On the other hand, the reports of widespread celebrations in heavily Arab-immigrant sections of European cities during the current Hamas attack on Israel, and the well known huge rise in attacks on native Jews by said immigrants (and, more worryingly, their descendants) in France in recent years, ought to be very concerning to Europeans.

>If caste-based discrimination is rampant then certainly it should be a bigger part of the screening process for immigrants. You can even refuse entry for immigrants from South Asia entirely - though I suspect this is a massively losing proposition for the US as a whole.

Maybe. Probably. At least the sheer diffuseness of the issue of caste-based discrimination—we can't quantify its existence, and as a non-Indian I cannot personally speak to its existence, one way or another—makes that calculation likely. If the problem were so widespread and visible that non-Indians were routinely witnesses to it, that might be a different story.

>What you cannot do (as you seem to be implying) is wholesale cast out American citizens based on their ethnicity or place of birth. Or at least I would hope not!

Nowhere have I suggested such. I have only said that if there is a widespread caste-based problem, one solution is to reduce or block further entry by those of South Asian origin to the US, and possibly revoke the visas of non-US citizen South Asians. The frenzied claims by others that I have proposed to revoke First Amendment protections on South Asians in the US, or that I advocate the expulsion of all South Asians (regardless of US citizenship), are only in their minds.

>I am a Canadian citizen, born in India. I have the exact same rights as any other Canadian - any Canadian telling me “your problems are not Canada’s” would be incorrect, and I would consider them a racist as well.

I disagree. As a naturalized Canadian citizen part of the duties and responsibilities that accompany receiving a new citizenship is to abandon the detrimental parts that came with the old. That includes prejudices and behavior that would cause societal turmoil in the new country. The onus is on the new citizen, and not the new citizen's new country.

>I don’t practice any caste based discrimination. I wouldn’t even know the caste I might have belonged; the caste of anyone I know; or how to determine caste!

Again, speaking as a non-Indian, how is this possible? Were you naturalized as a small child, and your parents never once spoke of the caste they belonged to? I thought every Indian in India was aware (whether they like it or not) of their caste.