I mentioned in a post above why I think Iran are attacking all over. I suggested it's to force the defenders to use up ammo.
This from CNN just now.
"Top executives from US defense contractors are set to visit the White House on Friday to discuss ramping up weapons production, a White House official told CNN.
President Donald Trump has sought to project confidence in US military capacity, saying Tuesday there was a “virtually unlimited supply” of US munitions and that “wars can be fought ‘forever,’ and very successfully, using just these supplies.”
Earlier Tuesday, the president told Politico that defense manufacturers are operating under emergency authorities to accelerate weapons production."
The US are short of ammo. This war was not planned.
If they run out of ammo for the anti missile defences before Iran runs out of missiles and drones, then the US bases are left open to attack.
Remember, Patriots are about a million each. And they don't fall from a production line like artillery shells do. Same goes for air to air missiles on jets.
Also remember stuff has to be held back because there are other countries in the world that will also be counting the ammo the US are using.