Defending the Driniumor: Covering Force Operations in New Guinea, 1944

The purpose of this Leavenworth Paper is to integrate American and
Japanese strategic, operational, tactical, and human dimensions into a
narrative form. The focus is on the 112th Cavalry Regiment because that
unit played a significant role in defeating a numerically superior Japanese
force that tried to outflank an American covering force. Official histories in
both English and Japanese languages illuminate the decision-making
processes of the combatants at the strategic and operational levels that
resulted in the deployment of men and their war-making equipment to the
Driniumor. Ultra adds the intelligence dimension to American decision
making. At the tactical level, however, events are less clear. For the
purposes of organization, three major engagements occurred along the
Driniumor River in July and August 1944. On the night of lo-11 July
1944, Japanese troops of the 18th Army broke through and overran
American covering force defenders an the Driniumor. An American counterattack
characterized by bitter fighting eventually sealed this penetration.
The third major battle-more correctly a series of company and platoon
level engagements lasting three weeks-raged around the south flank of
the American positions as the Japanese tried to turn the U.S. line. This
more specific level is difficult to reconstruct with exaetitude because of the
confused nature of jungle fighting when men only a few yards distant were
out of sight and earshot. Small parties of Japanese and Americans fought
and died in anonymity. Nevertheless, reference to contemporary military
reports and war diaries makes it possible to impose a degree of order,
necessarily arbitrary, on the operations and then to describe the fighting.