One American soldier called it "a green hell on earth." Monsoon-soaked wilderness, debilitating heat, impassable mountains, torrential rivers, and disease-infested swamps-New Guinea was a battleground far more deadly than the most fanatical of enemy troops. Japanese forces numbering some 600,000 men began landing in January 1942, determined to seize the island as a cornerstone of the Empire's strategy to knock Australia out of the war. Allied commander-in-chief...