Journalists and experts (both pro- and anti-war) were citing this months ago when everybody was talking about how expensive the war has been and how much was spent or used up in a day that could take years to replace. Since it’s old news now, I’m fuzzy on the details (might be mostly interceptors to stop drones?) but a simple search brings up results like these from major media (NYT, BBC, etc.), independent media, and beyond:

• Report: ​US burned through half or more of critical missile interceptors
• Rebuilding US weapons stockpile may ‘take years’ post-Iran war