Already exists (well, not iPhone, but...) https://www.samsung.com/us/business/solutions/industries/gov...

And accessories like cases and cables from Kagwerks: https://kagwerks.com/collections/smartphone-cases / https://kagwerks.com/collections/cables/products/usb-3-0-to-... (aside: their training courses are A+)

Combat iPhone is ok only in asymmetric warfare. Near-peer adversary will quickly figure out how to exploit it. Russia has already successfully targeted artillery strikes using location of Ukrainian soldier's phones (Android, but this difference is not very important).

We've been using iPhones in combat since at least 09.

CGI Federal/Raytheon has been working on something like this for the last 5-6 years for (AFATDS)

I'd argue that ATAK is closer to a "combat iPhone" system than AFATDS, which is uniquely focused on field artillery coordination.

https://en.wikipedia.org/wiki/Android_Tactical_Assault_Kit

I've worked on ATAK. It is a very capable combat tool.

How do they secure baseband?

Price: 10k$ per user. Fair enough if we’re billing the army for an app with a huge bug bounty.

This is old news. Look up ATAK.