Nick Bostrom wondered aloud in Superintelligence (2014) why states would allow individuals and private organizations to develop AGI. If one takes the possibility seriously, AGI would a source of immense power and any state would to take that opportunity for itself.

Edit: Not saying whether AGI is right around the corner, that's a different discussion. I'm just saying that a serious possibility of AGI and an understanding of possible consequences will make a state act.