The Japanese invasion of Bali on February 18, 1942, was a small operation with enormous strategic implications. A single battalion of the 48th Infantry Division came ashore, but what they captured mattered more than what they brought: Denpasar airfield, taken intact. That airfield put Japanese bombers within range of the ABDA naval base at Surabaya, the most important Allied port in the region. Dutch Admiral Karel Doorman could not let it stand unchallenged, but his forces were scattered across the sprawling Indonesian archipelago, and the invasion caught him off guard. There was no time to concentrate his ships into a coherent strike force. Instead, Doorman ordered what he had available to attack in waves - a plan that traded coordination for speed, and paid dearly for the exchange.

The day began with mixed results. An Allied submarine damaged one of the Japanese transports, and thirteen USAAF heavy bombers joined seven A-24 Banshee dive bombers in attacking the convoy, but they managed only to damage the transport Sagami Maru. On shore, the Balinese militia under W.P. Roodenburg deserted. By evening, the Japanese knew another attack was coming and began withdrawing their transports northward, each pair escorted by two destroyers. The first Allied surface wave - two Dutch cruisers and three destroyers - arrived off Bali's southern tip at 9:30 PM on February 19. They entered Badung Strait heading north, and at 11 PM the shooting started. Ten minutes of firing produced no damage on either side. The Dutch cruisers continued through the strait toward Surabaya, leaving the destroyers Piet Hein, Pope, and John D. Ford behind to press the attack.

What happened next took fourteen minutes and cost 64 Dutch sailors their lives. As Piet Hein came into range, shells from Asashio and Oshio crippled the Dutch destroyer almost immediately. At 11:16 PM, the two Japanese ships launched nine torpedoes. Piet Hein sank at 11:30 PM. The American destroyers Pope and John D. Ford exchanged fire with the Japanese but were forced to retire southeast, unable to follow the Dutch cruisers to safety. The Japanese commanders - Lieutenant Commander Goro Yoshii aboard Asashio and Commander Kiyoshi Kikkawa aboard Oshio - had demonstrated extraordinary aggression. Outnumbered and outgunned, they had attacked rather than defended, and the result was a decisive advantage. Then came the absurd coda: in the darkness and adrenaline, Asashio and Oshio turned their guns on each other, firing for several minutes before realizing their mistake. Neither ship was hit.

At 1:09 AM on February 20, a second Allied force reached the strait: the cruiser Tromp and several destroyers. Their torpedo salvos were easily avoided by the Japanese, and when the destroyers headed north through the strait, Oshio and Asashio confronted Tromp directly. The Dutch cruiser took multiple hits, suffering severe damage. A shell struck Oshio's magazine but failed to explode - had it detonated, the battle's outcome might have been very different. As the battered Allied ships withdrew north, they stumbled into two more Japanese destroyers, Arashio and Michisio. The exchange crippled Michisio, killing thirteen of her crew and wounding eighty-three, one of the few Allied successes of the night. Motor torpedo boats arrived last but achieved nothing. The battle was over, and the strait belonged to Japan.

The aftermath of Badung Strait reads like a cascade of disasters for the Allies. The damaged cruiser Tromp was withdrawn to Australia for repairs, removing her from the theater at the worst possible moment. The American destroyer Stewart, damaged in the fighting, limped into dry dock at Surabaya, where she was scuttled days later to prevent her capture by Japanese forces advancing across Java. In a strange postscript, the Japanese raised Stewart, repaired her, and pressed her into service as patrol vessel PB-102. Just one week after Badung Strait, on February 27, Admiral Doorman led the remaining ABDA fleet into the Battle of the Java Sea. It was a catastrophe. The cruisers Java and De Ruyter were sunk. Doorman went down with his flagship. The Dutch East Indies fell. Looking back, Badung Strait was the warning: four destroyers had defeated a force that outnumbered and outgunned them, exposing the Allies' fatal weakness in night fighting - a disadvantage that would persist until the Battle of Cape St. George in November 1943, nearly two years later.