Iran is quietly building a security perimeter around a suspected new uranium enrichment site, according to a nuclear watchdog group. The site, located near the Natanz nuclear facility, is believed to have the capacity to produce fuel for a nuclear bomb. The construction of the security perimeter suggests that Iran is concerned about potential military action from the United States and Israel. The discovery highlights the challenges of negotiating a new Iran nuclear deal and the need for greater transparency and access to ensure the end of Tehran's nuclear weapons program.