Last week, Israel struck four buildings at the Isfahan nuclear site, among them a uranium conversion facility. The IAEA said there has been no sign of increased radiation at Isfahan, which is roughly 350 kilometers (215 miles) southeast of Tehran.

The Middle East, a region perpetually on edge, finds itself once again at a critical juncture. As tensions between Iran and Israel simmer, a new and chilling development has emerged: Russia's explicit nuclear warning.