At what point could the united states no longer avoid involvement in world war 2

The United States was neutral up until the point where Japan bombed pearl harbor, which at this point, the United States was forced to join in the war against Germany.

interdependence is when all participating groups and individuals depend on each other. if you depend on one anothers goods, you end up trading in order to get the items you're looking for. (for ex: if i have food and you have water, we trade in order to depend on each other to live)