If you take the recent anthropic misuse report seriously, they don't need to "take over weapons" because they're actively being used to give a lift in capability to groups who already want to use weapons.

> The six cases in this section are divided into two parts. Part I covers four cases in which the actor in question used Claude to develop software for weapons themselves: a guided rocket program, in which the actors conducted a live field test; a design and proposal work on a system to intercept torpedoes; software for a drone swarm, tested in simulation, with its code loaded onto real boards; a targeting software for electronic warfare and for suppressing air defenses.

https://www.anthropic.com/threat-intelligence-report-septemb...