Danny Glover teaches constitutional law at Texas A & M University
"there was no national army and each colony was responsible for its' own defense."
The main threats were Indians and slave revolts, and revolts from non-slave tenant farmers. There was also quite a bit of ethnic conflict in those days (Scottish v/s Irish, for instance, or German v/s English). It wasn't the British. American landowners were disgruntled at the British for not allowing them to defend themselves from these domestic threats while the British Army was weak in the colonies. They were afraid a weak Federal government might do the same.