It's not only the US being special in this case.
The problem is pretty simple: there is money to be made and someone will do what the Pentagon wants. Will it be worse in capabilities than Anthropic? Probably, but as long as it can be used to wage autonomous war wherever the US military decides, it will be good enough.
Anthropic can stick to their beliefs as much as they want, but it will not change the outcome, maybe just postpone it a bit.
On an unrelated note, I think the Pentagon erred when it labeled them a supply chain vulnerability, they should have used the DPA to make them do what they need. Less drama and much cheaper compared to replacing them with a whole different company.
They can and do do this routinely. Many individuals get marked and regularly go through additional screening if their travel plans raise flags. This isn't even unique to the US... most Western nations do the same. If there is a serious brain drain risk, the US government can easily go all out and have the whole company put on the no-fly list.
Let's hope so, because I am not so certain.
When the US banded human embryo research did that erode trust? I didn’t hear anything about that at the time.