I don't want to sound insensitive, 3 thousand people is of course a tragedy, but on a scale of entire Earth I think it is preposterous for US citizens to get obsessed after this one when more kids are dying to malaria every single day or for multitude of other problems.
Looking from my point of view, it is that US rallies for some causes where it seems to suit US interests. There are so many countries that need help but in recent years whether a country gets US presence seems largely dependent on whether there is oil there and US is all too happy to turn their face away if the government of the oil-rich country is collaborating with US. This is a sore to many eyes and I just can't help to remember it whenever I hear of US trying to seem to be beneficiary in something.
This unfortunately adds fire to the trouble in the Middle East. If you are islamic radical it is extremely easy to recruit people by showing them factual, real, undeniable misbehavior of US. This lack of moral grounding is exactly the reason why actions by US do not bring expected effects. Local population treats US forces with resentment not because they are fundamentally anti-US but because they see US as a corrupt replacement for their current corrupt government.
A larger lesson is that you want somebody teach virtuous behavior you need to be able to show the virtue yourself or you are not going to achieve very much in terms of results.
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Also, my experience about downvotes is this kind of comment even if genuinely to show what's an example of sentiment outside of US, will typically get a lot of upvotes during US night time and then gets suddenly killed when US wakes up.
Just an interesting thing I noticed which, for me, validates the whole point that US doesn't like to acknowledge resentment it gets from most of the world and that US problems aren't actually the same as world problems regardless of how US would like to portray it.