Why was the Bonus March held?

Answer 1

Most people would say 'attack' but the true opposite is 'abandon'. Attack is sometimes (always?) a form of defence. To defend something or someone is to give protection from harm, so the opposite must mean leaving it/them open to attack. Alternately, 'surrender' could be considered as an opposite to 'defend' but this sometimes is the best option if resources are not up to defending actively- damage is minimised