Schools need to at least consider a contingency plan to protect students, who are minors. Obviously, students who are directly impacted by the ban cannot travel and will be excluded (which may be enough of an ethical reason to cancel the trip). But what plan does the school have in place if a student who should be admissible to the US is taken for secondary questioning, or denied entry? Generally these trips only have a handful of adult supervisors. Have they designated one as the potential "stay behind" to stay with the student and act as guardian, for example. Really, this planning should have already been in place, but is just coming into focus now.