Once the rocket is launched and full of the US gov's people/satellites/supplies/whatever, what difference does it make who owns it?
The US then contracted SpaceX to build Starshield, which is the same as Starlink but 100% controlled by the military. The US military will decide what Starshield can be used for.
With Starship, I assume the military wants to be able to decide where, when, and with what payload they can launch. If they were only contracting launch services, SpaceX might decline certain missions.
I'm pretty sure the US Government could have decided that for them as well. I haven't seen any evidence that they tried.
Or are you saying that the US could have stopped Starlink from being used to attack Russia (in the event SpaceX had agreed)? Again, I suspect that would have to be done via some new export control law.
Either way, the US military doesn't want to deal with the inevitable delays of the legal system. Much faster to just own the asset so you can do whatever you want.
Lots of US politicians made noises on television but that is not an official request.
The actual laws involved were actually fairly murky. SpaceX is required by US law not to service the Russian held parts of Ukraine (eg, Crimea) and Starlink itself doesn't want to find Starlink being regulated as a munition which has broad potential impacts w/r/t ITAR.
Were those just excuses? It is hard to say. But what is clear is that the US executive branch made no effort to remedy the situation.
Instead they left SpaceX in a position where they could be clearly condemned for either decision. The decision that SpaceX took was the one least likely to land them in court or jail. It's hard to blame them.
If the US government wanted, it could murder Musk, take the SpaceX staff hostage, and force them to do what they want.
There is a big difference between what people CAN do, what they can do without consequences, and what they want to do.
Any US adult can go on a killing spree with their car. What people CAN do is pretty useless information in a vacuum.
If that request is rebuffed, congress would have every right to attach political or purchasing consequences in order to make inaction undesirable. Regardless of ability to compel one can always cajole.
I have seen zero evidence that the US government made such a request.
From the military's perspective, war-fighting is their domain. Do we really want the US version of the strange drama around the Wagner Group? Blackwater was bad enough.
Along the lines of the other side asking themselves "is that rocket delivering cargo over there a military target?".
If SpaceX is 100% clearly non-military, then any SpaceX branded rockets delivering stuff aren't going to be (clear) military targets.
If SpaceX contracts Starship for risky missions, They would need to charge premium to cover loss of scheduled business and replacement in the case of failure.
In some situations, owning a dedicated vehicle could be cheaper than repeatedly paying this premium, even if SpaceX operates and maintains it.