500 Kilotons shuts down at least half the US if exploded at 400 - 500 KM AGL. LEO detonation can cripple VA - MA.
That’s what I thought.
This is assuming the Iranians have the technology to both build a sufficiently powerful device and explode it at the perfect altitude/position over the US or other target area.
If they can or get lucky, those animal onboard are toast.
Ping!