Australian and US forces attack Sanananda

As with the attacks at Buna and Gona, the Allies underestimated the strength of the Japanese forces. There were thousands more Japanese troops at Buna, Gona and Sanananda than the Allies expected. The Japanese were well-armed with machine guns and mortars. They were camouflaged in well-defended bunkers.

Australian and US troops suffered heavy casualties. The initial attack on Sanananda was a dismal failure, as were attacks all along the Beachheads.

Tropical disease was rampant. The Allies had to evacuate many sick troops, particularly with malaria. Commanders noted the mosquito was as challenging to deal with as the Japanese.

Supply was also difficult. The Allies could only get supplies through the swamp intermittently. When they did so, they were at great risk of enemy fire. After the Allies built airfields, aerial supply helped. It was the wet season, though, and often pouring with rain. Dense vegetation and well-camouflaged positions worsened the poor visibility, hindering the success of fly-overs. The battle dragged on until 22 January 1943, when the Japanese finally retreated.