Earlier this month, a doctor who had recently returned from Gaza provided shocking testimony about the scale of human suffering that Palestinians are enduring under an Israeli military onslaught that has entered its sixth month. There exist no moral arguments that can justify the continued sale of weapons to Israel by states that respect the principle of the universality of human rights.During my work as the United Nations’ special rapporteur on human rights defenders, Palestinian human rights defenders have emphasized to me the importance of a ban being placed on such sales, given that…