"Enormous Costs"?

Does he even understand what those costs could be? 

He still lives in the la-la land of the Desert Storm, where the US operated essentially unopposed in its assembly areas, but even in Vietnam, the US Army never experienced a fire impact (maybe Khe Sanh) which would compare to daily "deliveries" Iran can provide against any troops. These will not be some artillery and mortar impacts, that will be stand-off weapons, some of them with warheads measuring in hundreds of kilograms. This is a different game, and then there are recon and targeting ... but I said it before--the US doesn't have relevant experience with this. 

 

So, what COULD be the "costs" if the US decides to do "ground operation"? Depending on the scope (the US doesn't have required resources for large scale op, McCaffrey should know this) it will range anywhere between 10,000 + KIAs within limited scope op to hundreds of thousands KIAs if the US bogs down (which it will) in case of the "full scale" invasion of Iran in the first couple-three years. Vietnam War will look damn good compared to this.