I think you are missing the full potential of direct democracy. It is far more fluent and adaptable then the current form.
Well yes a military dictatorship is a real threat during any social change and when i have studied the history of revolutions I find the counter revolution to be our biggest problem. the counterrevolution usually happens from a violent overthrow of a government. So this is something we need to avoid offcource we will defend ourselves but we need to stay true to the non violence principle.
Nukes and guns are a problem, mostly heavy weapons. To avoid this I think the best solution is to make the social change so grounded in grass roots movement that it becomes an unconscious part of people. In Spain they had independent schools, vibrant unions, and ran project for a long time before they had the chance to take place in 1936 before they suffered the counter revolution because the Anarchist parties trusted the Communists, which turned on them and put them in prison and then it whent back to a state.
However I dont see something like this happening over night. It is a decade long process involving, Unions, Schools, Cooperative banks, Ideal sports organizations, Energy cooperations, and so on. We need to learn how to manage ourselves and expand that until the timing is right so that we can run everything overselves. There might be people trying to take power and threaten us, but should that scare away us from progress?
But dismantaling nukes is high on my priority.