The removal of the core of the Iran’s Arak heavy-water reactor and the filling of the cavity with cement meant that the Shia country had complied with the last of the conditions that preceded the lifting of economic sanctions imposed on it a decade ago. For Iran, the nuclear agreement's so-called "implementation day" ended more than 10 years of crippling sanctions and international isolation. The deal enables Tehran to become an active member of the international community once again.