China's occupation of Tibet is illegal. Turkey's occupation of "North Cyprus" is illegal. Trans-Jordan's annexation of the "West Bank" was illegal. Jordan ethnically cleansing all Jews from internationalized Jerusalem (1948-1967) was illegal. Holding Shalit without Red Cross visits is illegal. Lebanon randomly firing missiles into Haifa is illegal. US attacking Pakistani soil with drone missiles is illegal. Iranian arms smuggling into Lebanon and Gaza is illegal. Iranian arms trafficking to anybody is illegal. Iranian violations of its NPT obligations are illegal. European nations refusing to return Holocaust victims property even after their own courts have ordered them to do so is illegal. Yadayadayada. So you can see why Israel has no particular duty to obey this "international law", and why you can take your "international law" and stick it where the sun doesn't shine.
German authorities accused of playing down refugee shelter sex crime reports (Reuters)