No surprise here, Tehran doesn’t believe sanctions will materialize and have buried the lion’s share of their HEU stockpiles — and accompanying centrifuge cascades — in a massive underground complex near the Isfahan Nuclear Technology Center. Isfahan, Tehran’s version of Cheyenne Mountain, is well protected by advanced Russian radar systems, surface-to-air missile batteries, and roughly 150 meters of rock and concrete. The logistical hurdles involved in destroying such a facility would be nearly insurmountable.