If he can't get enough support because people are disinclined to become afraid of their neighbors in the next village or county, he'll inspire a few local thugs to make a raid on the neighbors. This will sure stir up some hostilities. So he gets his armed force, paid for by taxes. Now, on the other side of the border, there are some other enterprisers who play the same game. They run the very same deceit, and likewise organize an armed force to get even and protect their territory.
Sporadic raids happen on both sides.
This makes life dangerous for the people, who then genuinely begin to feel the need for increased protection. If they attack us again we'll punish them properly, so the enemy will think twice about messing with us. So now there is an established government with the power to enforce, a force it uses to disarm and disorganize the citizens. Once the State gains a monopoly on domestic force, the situation rapidly worsens. Taxes are gradually raised to the point where the people are driven into apathy, while the governors and their military establishment live high on the hog.