> That's the one glaring weakness of relying too heavily on missiles. They are expensive and difficult to manufacture. And they have a limited shelf life, making stockpiles also expensive
I don't think so. This observation completely misses the root cause, and it ain't missiles.
Armed forces size their stockpiles in terms of their short term needs focused on rapid reaction and deterrence. The goal is to be able to react to immediate threats and then shift the economy to a war economy to supply the effort in economically efficient ways.
What failed this time is that the trump administration was hoping to attack Iran without having to declare war, effectively starting a war without preparing for the war.
The results are obvious: the peace time stockpile was depleted at a time where the country was not prepared to replenish it. Trump shifter the us armed forces to deplete their stockpile while avoiding the responsibility of supporting them in their mission by taking care of supplies.
And so they ran out of ammo.
There are further compounding factors such as a lack of plan and lack of exit strategy. But placing your military in a state where they spend their ammo without any plan to ressuply it... You will have the same problem if you replace hellfire missiles with sticks and stones.