There has for many years been a contrast between using an adjective premodifier for nationalities ('Spanish troops', 'Chinese territory') and the bare name of the country ('Singapore transport', 'Brunei English'). It seems that, for small countries such as Singapore and Brunei, we prefer the name of the country instead of an adjective ('Singaporean', 'Bruneian'), while for larger countries, we use the adjective ('Spanish' rather than 'Spain').
However, that seems to be undergoing change. Look at this headline from the BBC World page of today:
Note the use of 'France soldiers' rather than 'French soldiers', as I would expect.
I have seen this for football teams in the past ('the France team' rather than 'the French team'); but this usage seems now to be extended to other domains. I have no idea why.