should in subordinate clauses expression personal reactions

'It is strange that a country shows consideration for another country's religion when they are at war.

This sentence was written at a time when the country in question (the USA) was considering suggestions to stop the bombing of Afghanistan during Ramadan. This is important, because if it were written after the fact, i.e., after the bombing had stopped in consideration of Ramadan, it would sound less odd. Should show would still be about equally likely in that case, I would guess, but in the case we are considering here, before there was any bombing halt and it was just a possibility, should show is definitely more likely, to the extent that shows sounds odd.

This usage can be relegated to the "putative" uses of should, which are described by Quirk et al. as indicating that "the speaker entertains, as it were, some 'putative' world, recognizing that it may well exist or come into existence" (§4.64). In simpler terms, it indicates a state of reality somewhere between real and conditional or hypothetical.

Swan describes it as expressing "personal reactions to events" (for instance, with words like amazing, interesting, shocked, sorry, normal, natural, it's a shame)," and we can add strange to this list, as well as many other words expressing emotion or "mood" (Quirk et al. §4.64).

This usage is found in some common expressions, e.g., Funny/Interesting you should mention that...

Swan says that should is more common in this usage in the past tense, presumably as in his example

I was shocked that she shouldn't have invited Phyllis.

but to my American ears this is much less likely than the indicative

I was shocked that she didn't invite/hadn't invited Phyllis.

although Swan says both are possible. It seems reasonable to me to speculate that should is actually less likely in the past, however, since past facts are characteristically known and less likely to be characterized as "putative."

Swan's other examples are:

It's astonishing that she should say that sort of thing to you.
I'm sorry that you should think I did it on purpose.
Do you think it's normal that the child should be so tired?

In all of these sentences, I think Quirk et al.'s characterization holds: should renders the action or state of the verb somewhat less than factual, or less bluntly factual, compared to

It's astonishing that she says that sort of thing to you.
I'm sorry that you think I did it on purpose.
Do you think it's normal that the child is so tired?

Here there is no doubt expressed about the facts. In the sentences with should, the verbal actions or states are presented less as ideas and more as ideas.