The word 'must' is not a word israelis like to hear. Israelis don't want to be forced. Even if their actions are illegal, israelis will tell you you're wrong. Even if their country's policy is against the law they will tell you 'we had no choice'. Self justification, arrogance and feeling of superiority....the only choice is sanctions but israelis will say you're an antisemite. You can't win...but they lose as well.
Report: Iran's Culture Ministry refuses to allow Barenboim to perform in Tehran (DPA)
from the article: UN chief to Netanyahu: Israel must refrain from settlement construction