LLMs could be interesting geopolitical roleplayers if instructed to faithfully assume the leadership traits or cultural biases of the their intended role, especially in games with expressive diplomacy systems like Stellaris or Europa Universalis. It could also make the diplomacy experience a lot richer because the LLM is able to interpret ligusitic tone and other verbal cues. The modern diplomacy experience is basically just a dialog tree with stats and dice rolls attached to it.