Anyway, I'm not saying the wall isn't condemnable, but in order for someone to say something is "illegal" there usually has to have been a clear preexisting rule (in this case a treaty or convention), and there was not. Also judicial bodies generally try to avoid weighing in on things that are being debated politically (example: the US supreme court system's reluctance to weigh in on gay marriage) because that politicizes the judicial body and casts questions on their legitimacy. I think it may be a highly viable opinion that the wall is wrong, but my opinion of the legitimacy of the ICJ has gone down significantly because they decided to weigh in on the subject.
Re: devil's advocate time
Anyway, I'm not saying the wall isn't condemnable, but in order for someone to say something is "illegal" there usually has to have been a clear preexisting rule (in this case a treaty or convention), and there was not. Also judicial bodies generally try to avoid weighing in on things that are being debated politically (example: the US supreme court system's reluctance to weigh in on gay marriage) because that politicizes the judicial body and casts questions on their legitimacy. I think it may be a highly viable opinion that the wall is wrong, but my opinion of the legitimacy of the ICJ has gone down significantly because they decided to weigh in on the subject.