This article is informed in part by a contemporaneous Australian account published in the Sydney Morning Herald on 18 February 1946, reproduced below. That article examined claims raised during United States Senate hearings into the Pearl Harbor attack and addressed Australia’s handling of a warning originating from the Netherlands East Indies shortly before war broke out in the Pacific.
In the years leading up to the Pacific War, the Netherlands East Indies (NEI) regarded Japan as its principal strategic threat. As early as 1932, the Royal Netherlands Navy had developed radio interception capabilities aimed at monitoring Japanese naval communications. By late 1941, Dutch intelligence officers in Batavia (now Jakarta) were closely following Japanese signals, naval movements, and diplomatic developments as tensions escalated across the region.
By November 1941, the Dutch assessment was clear: the risk of war had become immediate. Japanese negotiations with the United States were collapsing, while Japanese naval forces were moving steadily south. In response, Dutch authorities in the NEI decided to activate previously agreed war plans with Australia and formally informed Canberra of this decision.
The Dutch message and its meaning
The Dutch communication did not identify a specific target for a Japanese attack. Instead, it conveyed that the Netherlands East Indies had put its war plan into operation in response to Japanese naval movements and requested immediate Australian cooperation under existing defence arrangements.
This message was a strategic warning rather than a tactical one. It signalled that hostilities were expected imminently and that coordinated Allied action was now required. It did not mention Hawaii, Pearl Harbor, or a direct attack on United States territory.
How the Dutch warning reached Australian and US authorities
In Australia, the Dutch decision was conveyed through formal liaison channels. On the evening of 4 December 1941 (Australian time), a conference was held involving senior Australian and Allied officers, including Air Chief Marshal Charles Burnett, representatives of the United States military mission, and the Dutch liaison officer from Batavia, Commander G. B. Salm. At this meeting, Dutch naval intelligence from Vice-Admiral Conrad Helfrich was discussed, including confirmation that Japanese naval forces had crossed critical geographic thresholds and that Dutch war plans were now in effect.
Among those present was Van Santvoord Merle-Smith, the United States military attaché in Australia. Merle-Smith’s subsequent despatch to U.S. commanders reflected the Dutch decision to execute war plans in response to Japanese naval movements, a point later central to post-war discussions in the United States about pre–Pearl Harbor warnings.
Merle-Smith came from a New York family with Dutch colonial roots through his mother’s Van Santvoord line, a historical detail that reflects the layered Dutch–American connections present in Australia on the eve of war.
Australia’s response
The Dutch message was received formally in Melbourne on Friday, 5 December 1941. It was brought directly to Prime Minister John Curtin by Sir Frederick Shedden, Secretary of the War Cabinet. Curtin immediately ordered the reassembly of the War Cabinet, which met within half an hour and approved the implementation of the requested Dutch–Australian cooperation.
That same evening, Curtin briefed senior journalists on the gravity of the situation. By Saturday morning, 6 December 1941, major Australian newspapers were already reporting that war or peace in the Pacific was likely to be decided within days, that Japanese forces were moving southward, and that joint defence plans between Australia and the Netherlands East Indies had been activated.
The Dutch warning was therefore treated with urgency and seriousness at the highest political and military levels in Australia.
Information sharing with the United States
At the time, both Australia and the Netherlands assumed that the United States was fully aware of the deteriorating strategic situation. Japanese naval movements were already being observed by U.S. intelligence, and the activation of Dutch–Australian defence plans was understood as part of a broader Allied response to the Pacific crisis.
The Dutch warning did not provide new intelligence about the location or timing of a specific Japanese strike. Rather, it reinforced the shared Allied assessment that war was imminent.
Why Pearl Harbor was not anticipated
Although war was expected, the location of Japan’s first major attack was not. Allied governments, including those of Australia and the Netherlands, anticipated that Japanese aggression would initially be directed toward Southeast Asia, Malaya, the Netherlands East Indies, or possibly the Philippines.
A direct strike on the United States Pacific Fleet at Pearl Harbor lay outside prevailing strategic expectations. This was not due to a lack of warning that war was approaching, but to a shared misjudgment about where Japan would strike first.
Prime Minister Curtin’s reaction when informed of the attack, disbelief, reflected this wider Allied assumption.
What the Dutch warning demonstrates
The Dutch warning before Pearl Harbor illustrates several important points:
Dutch intelligence in the NEI correctly assessed that war was imminent and acted decisively.
The Netherlands formally activated joint war plans and informed Australia without delay.
Australia responded immediately and implemented the requested cooperation.
The failure to anticipate Pearl Harbor stemmed from a broader Allied misreading of Japanese strategic intent, not from neglect of the Dutch warning.
From warning to integration
The events of December 1941 exposed the limitations of pre-war intelligence coordination among the Allies. In the aftermath of Pearl Harbor and the fall of the NEI, this changed rapidly. Dutch intelligence and communications were reorganised from Australia, with new wireless stations established at Batchelor and Craigieburn and the creation of the Netherlands Forces Intelligence Service (NEFIS). By 1944, Dutch intelligence headquarters had moved to Camp Columbia at Wacol, near Brisbane, where it became fully integrated into Allied operations in the Southwest Pacific.
The Dutch warning before Pearl Harbor belongs to the final days of the pre-war intelligence environment. The intelligence structures rebuilt in Australia represent what followed: a more coordinated Allied system shaped by the lessons of early wartime failure.
Paul Budde February 2026, with the assistance of Peter Dunn
