it has nothing to do with the way law operates in the UK
the prez has various right and duties - and basically the plaintiff said that the prez had a duty to specify Jerusalem as Israel and the counsel for the prez said he had a right to write what he wanted
the prez won
there are all sorts of features in this case, we dont have such as the presidents executive privilege ( various things that cant be questioned in the courts) and whether a court can strike down a statute ( no in the UK )
it is likely that such a question in the UK would be decided on the lines of ex parte Kuchenmeister - which is here
http://swarb.co.uk/rex-v-bottrill-ex-parte-kuechenmeister-ca-1946/
where the courts would accept absolutely a certificate from the foreign office specifying the country that Jerusalem is in
Jackdaw would have done this case in his law course in Dham in the sixties - it has changed a bit since then as a result of ministry bad behaviour over cases like Matrix Churchill - and the courts may now look behind the certificate and look at the reasons - ministers have only themselves to blame for this devt