The autonamous technology is already out there. Look at the DARPA Grand Challenge. And, it's not just big corporations but universities and small organizations. If you are talking about the guns. Well, you may not trust the government with those big guns with the checks and balances. But, who would trust you and others with those guns but without those checks and balances?
So, you talk about future dictators having more tools of torture. Do you think they are not doing great with the tools they have now?
I'd rather return to the "No Standing Army" policy of individual state militias that can be called up to defend our borders in the event of a real declared war.
I kind of like this idea but it is not practical in this world. The US is a big target for many reasons. The top guy always is. Can a militia get up to arms quickly enough? Can they militia men have the training that regular army can have? No to both. It would put us in a loosing situation against our enemies. This is no longer practical.