While the world has focused on discussions over Tehran's nuclear capability, human rights in Iran have suffered severe setbacks.

By, in effect, "de-linking" advances in this area from the economic incentives aimed at ensuring Tehran suspends uranium enrichment, the European Union has sacrificed the Iranian people's rights in order to secure a nuclear deal. This moral failure makes it even more important for Washington to join the talks and put human rights at the top of the agenda. US involvement in the talks will provide the international community with the security guarantees it needs, while ensuring no deal is struck that would be detrimental to Iran's faltering democratisation.