Concern grows over Iran enriching uranium to near weapon-making level

A top defense official says Iran could produce enough fissile material for one nuclear bomb in about 12 days. This is the tightest assessment of Iran's "breakout time" yet and comes after an IAEA assessment finds Iran has successfully enriched uranium to 84% purity — 90% is the level needed to make a bomb.

Here & Now security analyst Jim Walsh, a senior research associate at the Massachusetts Institute of Technology's Security Studies Program, joins us.