BBC News: The Gulf states' defences against Iranian drones and missiles

There is a serious defensive challenge the Gulf states face. They've already expended a very significant number of interceptors... The cost asymmetry is very much in favour of Iran because many of the munitions that they're using - cheap one-way attack drones - are considerably easier And cheaper to produce than the things that are being used to shoot them down. Of course, there are certain absolute constraints on interceptor production in terms of long lead items... which means that one can't really scale up even if the Gulf states, for example, wanted to procure more. So I think a lot will hinge on how much capacity the US is willing to draw from other regions in the world if this becomes a defensive challenge, and also how efficiently the states can intercept cheaper targets with something other than an expensive interceptors.