Apart from the multiple US–Soviet nuclear crises of 1983, there has probably never been a more important time for Australians to consider the immediate implications of hosting Pine Gap. In the event of war on the Korean peninsula, Pine Gap hardwires Australia into US military operations, whether Canberra likes it or not.

The extraordinary transformations of Pine Gap in the last two decades — in its size, range of activities, technology, organisation and most importantly in its function and role — mean this hardwiring is both literal and metaphorical.

Three of Pine Gap’s surveillance systems are relevant to US military operations on the Korean Peninsula: its space-based interception of many forms of military and political electronic emissions; its ground-based monitoring of downlinks from adversarial (and allied or friendly) countries’ communications and navigation satellites; and its space-based infrared detection of the heat blooms of missile launches, jet aircraft afterburners, explosions and major fires on the earth’s surface.

In recent months, Pine Gap’s tasking schedules have been in overdrive contributing to updates to US Pacific Command’s and Strategic Command’s understanding of the North Korean Electronic Order of Battle — the key to shortening the attrition rate of US attacks on North Korean assets if war starts. These three systems at Pine Gap, mashed together with data from other surveillance platforms and intelligence sources, provide the Pentagon with vast quantities of locational data on radars, army units, missile defences and political and military leadership, as well as early warning signs for a nuclear attack on the United States.

Technically, all activities conducted by the United States at Pine Gap happen with the ‘full knowledge and concurrence’ of the Australian government. Today, Australia has all-areas access at Pine Gap, and a roughly equal number of US and Australian personnel at the base work side-by-side in the same areas. Pine Gap is indeed a ‘joint facility’ in ways that the US companion station at Menwith Hill in the United Kingdom is definitely not.

But this does not change the reality that Pine Gap is a US facility to which Australia has a fairly high degree of access. It was built by the United States, is funded by the United States and can only function as part of the US global technological system.

Australian personnel at Pine Gap contribute to the implementation of both Australian and US task scheduling, but when push comes to shove, US intelligence requirements determine the scheduling and task setting of Pine Gap’s operations. The output from these systems, including the results of a great deal of processing and analysis of signals intelligence, are transmitted to the United States by optical fibre and satellite. The infrared detection satellites are operated entirely remotely from the United States, and their downlinked data moves automatically unprocessed to the United States.

In theory, an Australian government could decide that it does not want Pine Gap to be used for one or more of the roles outlined above. But the level of technological integration alone militates against this in times of crisis. This is especially clear in the case of Pine Gap’s currently irreplaceable role in cueing US, Japanese and South Korean missile defence systems to lock on to incoming missiles.

But well before the level of nuclear war, which was Pine Gap’s focus for decades, Pine Gap now plays a vital role in US real-time battlefield operations worldwide, including in the wars in Afghanistan, Iraq and Syria. Interception of cell phones to provide geolocation data for US drone attacks is a well-known part of Pine Gap’s work, but this is just the edge of its battlefield role. Tests on the Korean Peninsula as much as 20 years ago demonstrated Pine Gap’s real-time ability to provide location data of emissions from adversarial artillery batteries, enabling rapid counter-battery fire from US and South Korean forces.

Pine Gap today is a US battlefield asset, and if President Trump’s threat to ‘totally destroy’ North Korea shifts from rhetoric to policy, Australia will automatically be involved in the second Korean War, unless the Turnbull government turns away from ‘joined at the hip’ rhetoric of alliance to join the German blanket rejection of its — and Canberra’s — ally’s belligerence.

Long symbolic of the ANZUS alliance, Pine Gap’s new roles and technologies have changed the character of the alliance itself, hardening linkages and closing space for choice. Now is the time for Australia to consider its long-term strategic interests in East Asia distinct from those of the United States and to consider how to disentangle itself from the increasingly dense network of alliances — at least to the point where a choice can actually be made.

Richard Tanter is Senior Research Associate at the Nautilus Institute for Security and Sustainability, and teaches International Relations at the University of Melbourne. He is chair of the Australian Board of the International Campaign to Abolish Nuclear Weapons. Together with the late Desmond Ball and the Canadian SIGINT specialist Bill Robinson, he has been working on a series of technical and historical papers on Pine Gap published by the Nautilus Institute.