CSIS expert Cancian estimates that the US may have stockpiles of around 1,600 Patriot missiles – which in recent days will have been depleted. While he says the US can keep the air-to-ground war going for a "long time", the air defence war is "more iffy".
"If President Trump is willing to draw down on the number of Patriots, then I think we can outlast the Iranians – but it will come at a cost of risk in a potential Pacific conflict."
The fact that Trump is set to meet US defence firms later this week is a sign that there is some concern about weapons stocks. But the US Defence Secretary Pete Hegseth insists "Iran can't outlast us". On this, he's probably right.