Many Australians misunderstand the ANZUS Treaty. Even those who should know better, including ministers, senior ministerial advisers, academics, and commentators, have either overstated or understated its significance. Simply put, the US–Australia alliance has meant different things to different people.

To some, it represents a blank cheque for Washington to honour and for Canberra to fill in an unconditional and unqualified manner. To others, it’s a commitment merely to consult, accompanied by only a vapid declaration of intent to act.

To some, it’s a reason for Australia to make only a token defence effort, since ANZUS is thought to be a sure and certain guard in all circumstances against defeat in war. To others, it’s a monkey on our backs, pushing us into unnecessary embroilment in another nation’s conflicts.

To some, it’s a safeguard against the resurrection of a defeated and occupied past enemy. To others, it’s a commitment to go to the defence of that former foe.

To some, it’s a cast-iron guarantee of safety. To others, it’s a scrap of paper blowing in the winds of changing circumstances, executive fickleness, and legislative waywardness.

To some, it’s an insurance policy against disaster. To others, it’s a means not of compensating for the consequences of disaster but a policy of deterrence: to avert disaster or at least limit disaster’s harm.

To some, it’s a shutting of the back door against an enemy, which sees an opportunity when Australia’s forces are engaged on the other side of the world. To others, it’s a front door to involvement in something we would rather stay out of. And to some, it’s a means of keeping our independence. To others, it’s subjugation to subservience.

The reality is that ANZUS, far from being legally enforceable, is a political agreement, at most a binding of oath.

By engaging each party to the same obligations and commitments, it leaves to each the determination, as particular circumstances arise, of the meaning each gives to the treaty’s terms (such as “Pacific Area”, and “armed attack”) and of the content each gives to the treaty’s commitments (such as to “act to meet the common danger” and to develop the capacity to resist armed attack “by continuous and effective self-help and mutual aid”).

Of course, no security treaty can be too precise and detailed in its terms, in particular by laying down in advance how each party will react and act when the time comes. Circumstances all too often change. Moreover, no party, in an alliance of truly independent states, can prescribe in detail, let alone in advance, the precise reaction of another party; the power of national decision-making is a prerogative of sovereignty.

So ANZUS does not give Australia that certainty of Washington’s reaction in our time of trouble to justify thinking that the US is our guarantor. It is not bound in law and certainty to do exactly as we want or expect in making up for our inability to meet our prime national obligation to preserve our territorial integrity and political independence.

Is that to say that the US commitments under ANZUS, including the commitment to “act to meet the common danger”, are valueless in deterring armed attack against Australia, or in helping us to prepare for it, or in fighting it should deterrence fail? Was the Marine band at the formal signing of the ANZUS Treaty by the three parties in San Francisco in September 1951 adding a note of realism by playing two currently popular songs “I’ve Got Plenty of Nothing” and “It Ain’t Necessarily So”?

The answer to both questions is no. The likelihood is that the US would come to our aid if Australia were attacked. After all, since any attack would amount to a violation of our territorial integrity or political independence, the US would probably already be involved, as in the Pacific War, and in view of the 2012 US decision to station Marines in Darwin for six months every year. And if not already involved, the US would not wish to see Australia sink. Neither would it wish to unnerve its many other allies around the world by failing to come wholeheartedly to the safeguarding of a treaty partner.

Still, whether in circumstances of our direst peril or of something somewhat short of that, the actual content the US gave to its ANZUS commitment “to act to meet the common danger” would be for Washington to determine in all the circumstances at the time. And in reaching its decision, it would have regard not alone to Australia’s wishes as to the speed, composition, and purposes of the US’s action but also, and perhaps primarily, to many other considerations.

For one thing, the source, nature, and severity of the threat to Australia and to America’s own security would need to be considered. Not to mention the extent to which Australia was capable of handling the situation on its own.

Other factors worth considering include whether we had done enough in developing our own military capabilities to satisfy our ANZUS Article II commitment to engage in “continuous and effective self-help”, or were free riders relying on the US to bail us out of the spot we had got ourselves into by our own inadequacies. Or whether Washington thought we were acting sensibly or had brought the situation down on our own heads by having adopted foolish and unnecessarily provocative policies.

Or whether we had been emboldened into over-tough policies by convincing ourselves that the US, whatever the circumstances, would always come to our rescue should we get in over our heads. Or whether the US thought the outcome we wanted was in accord with reality and US interests. Or how acceptably we had acted in the past when the US had been in trouble. Or where else in the world, and to what extent, the US was already militarily involved, or likely soon to be. Washington would also need to bear in mind the effect on its other alliances if it were to decide to leave us on our own or even in what we considered to be a lurch.

And yet, despite these legitimate considerations, ANZUS undoubtedly ensures Australia’s protection.

While ANZUS is not and cannot be a true guarantee that each party in some future circumstance will do exactly as the other wants or expect — and while the Treaty is not and cannot be an insurance policy — ANZUS is clearly a powerful deterrent to prospective enemies. While Australia cannot be certain beforehand exactly what content the US will give to its Article IV commitment to “act to meet the common danger”, neither can a prospective enemy.

A prospective enemy must be well aware of the extremely large US capabilities, both from the size of its economy and its unmatched ability to use force, notably because of its nuclear weapons, great maritime strategic mobility, extraordinary intelligence collection means, superior command and control communications, and large logistic capability.

That last is often undervalued. But as German field marshal Erwin Rommel, elaborating somewhat on Napoleon’s “an army marches on its stomach”, wrote: “The battle is fought and decided by the quartermasters before the shooting begins”. It’s a truth his masters (though not Dwight Eisenhower’s) failed to understand. The ratio of combatants to non-combatants in the German army was two-to-one, whereas the corresponding US ratio in the European theatre was oneto- two. The corresponding figures in the Pacific theatre were Japan one-to-one, the US one-to-eighteen.

Moreover, the US not only devotes more than others to logistics manpower, it has extraordinary assets in strategic and tactical lift by air and sea. Former Australian prime minister John Howard unavailingly asked for “US boots on the ground” in the East Timor operation in 1999, but the Australian effort, despite Timor being so geographically close, could not have been mounted and sustained without US logistical help — as well as intelligence, communications and political help — and with three US ships just over the horizon, one with 600 Marines aboard. So what the US can bring to the table is much more than weaponry and armed forces.

Still, some argue that a large defect in the Treaty is that when a Party suffers an armed attack its Treaty ally is not required to bring its armed forces into combat. The US can, however, give extraordinarily useful content to its legally binding commitment to act to meet the common danger. East Timor in 1999 comes to mind here, but there are two more examples.

During Konfrontasi, in 1963 Washington and Canberra accepted that ANZUS did not apply because the Australian forces engaged in Malaysia against Indonesia were not being subjected to Treaty “armed attack”. From the outset, though, Washington made clear to Jakarta that the US was firmly against what it was bent on doing, and frequently reminded Indonesia of the existence of ANZUS and of the possibility of US action under it if Indonesia went too far. That political pressure made plain that the US was an ANZUS party, not a disinterested party intent on brokering a peaceful solution, and that bolstered the diplomatic spine of Australia. By March 1965, according to the diplomatic historian Matthew Jones’s Conflict and Confrontation in South East Asia, 1961–65, President Lyndon Johnson had come to the conclusion that:

At the end of the day, should it become necessary, he would be ready for major war against Indonesia, if she raises the stakes too high … When asked if this was because of ANZUS, Secretary of State Dean Rusk replied in the affirmative, adding ‘and because of our relationship with you. We will back you if necessary to the hilt’.

When people evaluate the ANZUS Treaty, they almost always focus on the Article IV commitment by the parties to “act to meet the common danger”. But perhaps even more useful to Australia is Article II: the commitment by the Parties to engage in “continuous and effective self-help and mutual aid” in order to “maintain and develop their individual and collective capacity to resist armed attack”.

For Australia has done well in satisfying its commitment to “mutual aid”. We’ve hosted some half-dozen joint Australia–US defence facilities (some with several separate installations), even though they were and are nuclear targets because they are of such defence and intelligence-gathering value to the US and Australia. And we’ve provided combat and political help to the US in non-Pacific Area theatres, such as the Gulf in 1990–91, Iraq in 2003–09 and Afghanistan since 2001.

For its part, the US has done much of wide value for Australia by way of mutual aid. After all, it has provided most of the equipment for the joint facilities and shared much of the product. It provided the political and logistical help for the (non-ANZUS) East Timor stabilisation operation led by Australia. It provided political and, in the end, threatened help in Konfrontasi. More recently, President Barack Obama’s decision to station up to 2,500 US Marines in northern Australia for six months every year on a rotational basis has upgraded the alliance.

Beyond all that, without ANZUS, as Rod Lyon of the Australian Strategic Policy Institute has pointed out:

A host of military–to-military activities would disappear. Included among these would be the opportunity to train and exercise with the world’s most advanced conventional power, Australian access to high-technology military equipment and high-quality intelligence, interoperability between the two nations’ forces and access to key space support services for the ADF … [and the opportunity for] each of the Services to work closely with its US counterpart to maximise the practical benefits of cooperation.

[Were these things] to disappear, Australia’s military capabilities would be profoundly affected. The ADF would be a mere shadow of its current self. It would have few opportunities to exploit technological “edges” in order to help offset its small size. The arrangements that have developed under the ANZUS umbrella have been instrumental in allowing Australia to deploy some of the attributes of powers larger than we are.

So, quite apart from the benefits and limitations of the Treaty, the US is simply essential for our security.

Our security circumstances are not a function of propinquity. They are to be found not only in our vicinity but also in “our” region of South-East Asia and the south-west Pacific (such as the attempt by communist North Vietnam, backed by the Soviet Union and China, to take over South Vietnam and probably to go on to topple other South-East Asian countries, notably Thailand), in North Asia (such as the attempt by North Korea, backed by the Soviet Union and China, to take over South Korea), in the Middle East (such as the attempt by Iraq to absorb Kuwait and its oil and probably to go on in due course to Saudi Arabia), and in Europe (such as the expansionist attempts of Germany in the two World Wars and of the Soviet Union in the Cold War). If those European security circumstances had gone the other way, Australia’s territorial integrity and political independence would have come to an end.

If those security circumstances elsewhere had gone the other way, the result for Australia would not have been so cataclysmic or immediate. Still, Australia’s security circumstances would have been seriously worsened, making problems for our future.

So the shape of the world, not just the shape of what is comparatively near, matters profoundly to Australia. Our problem, though, is that we are at present too economically and militarily small to be able to influence fundamentally our security circumstances near or afar.

Fortunately, the US exists with the same interest in the shape of the world and the same need to prevent serious deterioration in its security circumstances lest the defence of its territorial integrity and political independence become necessary. It is also fortunate that the US decidedly does have the various means, and has shown it is prepared to use them, to influence markedly the shape of the world. So Australia’s problem is largely solved by the existence of the US. And in helping Washington in its efforts, Canberra is helping itself.

Australia is fortunate that the US, although still the world’s leading power in every dimension, is not and cannot be the world’s hegemon, able to impose its will and leadership all across the globe. If that were the case, a country would need to be both the paramount military power in Eurasia, and the world’s paramount naval and naval-air and space power. The US can only ever be one of those two powers. So it cannot rule the world and tell us what to do as though it were the Soviet Union and the rest of us were its satellites.

The value to Australia of the ANZUS Treaty lies not just in Articles IV and II but also in Article III (the joint commitment to consult when danger threatens any Party’s “territorial integrity, political independence, or security”) and in Article VII (establishing a council of ministers, now known as AUSMIN, of which Australian External Affairs Minister Richard Casey said in his ANZUS statement to Parliament in July 1951 was “no less important than the mutual defence obligation and perhaps of even greater long-range signification”).

Indeed, even before ANZUS came into being in 1951, External Affairs Minister Percy Spender in September 1950 called on President Harry Truman to try to get his support for “some regional security arrangement, with a reproduction in substance of Article 5 of the Atlantic Treaty”. But the purpose of any such arrangement, Spender told Truman, was not just, or even principally, to get a US guarantee of Australia’s security but to get Australian membership of an “organised political body … for determining global strategy … The point, I reiterated more than once, was that since Australian lives would be involved in any world war … Australia was entitled to a fair say in the determination of the events upon which war, or no war, might depend”. In particular “Australia was entitled to a voice in determining the course of events … in the whole area of the western Pacific.”

Articles III and VII did not quite give Australia all that to which Spender averred we were entitled. Yet it is fair to say that current arrangements for annual meetings of the Australian and US foreign and defence ministers — and the fullness, frankness, and wide range of Australian–US political, defence, and intelligence exchanges throughout the year — come pretty close to reflecting Spender’s vision.

Of course, how attentively Australia is listened to in Washington, how much influence it is accorded, cannot be asserted but has to be earned — by the significance of our military, political, and policy contribution to the joint effort led, and inevitably mainly fashioned, by the US. Our place in Washington has to be constantly earned, not just by past efforts.

Moreover, it has to be earned without our losing our independence of judgement and of decision-making as to what is in Australia’s national interest. Neither do we want to end up in Tacitus’s trap: Subjectos nos habuit tamquam suos, viles ut alienos — he has little regard for us because we have surrendered ourselves, and he keeps us under his thumb as if we were his to order about.

One final point: our relationship with the US through ANZUS is helpful outside the strict area of security and defence. Other countries growing fast in many aspects of power might pose no current military threat to our security or defence but be quite capable of using their power to increase their international influence and to advance their foreign policy and national security priorities in other ways.

In particular, power in its various forms, including military muscle-flexing; diplomatic pressure; or financial inducements through loans, investments, and commercial enticements could be used to persuade and in effect bribe others, less powerful in themselves and in their connections, and so more pliable, into shaping their internal and external policies to accommodate the interests and wishes of the more powerful.

If Australia were to be subjected to such coercive pressures by a rising power, the structure of our alliance relationship with the US would make us less vulnerable even if the circumstances were not such as to call for forcible US intervention on our behalf. Bear this in mind before critics of the alliance casually and cynically dismiss the Treaty’s significance.