The Iranian regime should, at the very least, commit itself to halt uranium enrichment at 20%, a figure short of the threshold needed to produce weapons. Having had direct meetings with both Iranian President Mahmoud Ahmadinejad and Supreme Leader Ayatollah Ali Khamenei, Erdoğan was in a unique position, as a prime minister of a NATO country, to convey these critical messages to a regime whose top-level decision-making processes remain as opaque as ever to the West.