> The second is that it violates the first amendment of the US's own constitution, which uses universal language, not discriminating between citizens and non-citizens, nor between inside and outside US territories, nor between nationals and foreigners.
I'll push back against this interpretation since no matter what any country's constitution says, no national constitution can ever really apply to foreign nationals on foreign soil doing their own thing (diplomatic missions being a notable, narrow carve-out for that).If you take this universalist interpretation, that would mean it's fine for US citizens to truck guns into Canada (which they can't, but they still occasionally do, largely for much more boring reasons than believing there's a constitutional justification) with no restrictions because the implication is that the US constitution supersedes other laws in other countries.
It is, however, against the spirit of the document, and it's arguably an abuse of the existing framework of sanctioning organizations which take part in terrorist efforts. It's another case of the US legal system falling short because of an assumption of good faith by those in power.