The authors of the new Defence White Paper deserve our sympathy. They have to address the widest range of challenges to our national security that has ever been faced.

We may be out of the era of bellicose great powers confronting each other with clear willingness to go to war as in 1914 and 1939–41, but what a complex era we have moved into. The effects of climate change are becoming evident. Masses of people are on the move to escape starvation, flooding and malfunctioning regimes. Refugee flows are likely to increase. Hostility is building between the West and Islamic radicals. We may have to face terrorist strikes on a new scale and across a wider area. We need to tighten our border controls. We may want to respond positively to calls by the UN or our allies for help in intervention. We live in a world where nuclear proliferation is continuing slowly but surely, as the North Koreans recently demonstrated.

So how does Australia protect itself acceptably against those dangers within a defence budget of close to 2 percent of GDP? It’s tempting to say that we cannot, and the Government will clearly try to prevent a major cost expansion. So where should our defence priorities be? For myself, control of our surrounding sea space comes first, and for day-to-day purposes that means a strong patrol boat force backed by some major surface combatants and a comprehensive aerial reconnaissance capacity.

If regional order breaks down and moderate sized forces are sent against us, we will need a substantial army. This will compel an enemy to attack with large numbers, which would be much more difficult to assemble, move and supply, and would also offer a better target for counter-attack by our naval and air forces.

What do we have by way of an army? It doesn’t take long to tell. We have seven (regular) battalions of the Royal Australian Regiment, 14 reserve battalions, five special units (SAS, Commandos, etc.), a tank regiment a cavalry regiment and six reserve cavalry units. Out of that number we can squeeze a brigade-sized force, the minimum that we should deploy on intervention missions. But for home defence, say of the north-western sector of our continent, we cannot cover much. A battalion, well supplied and supported by artillery and tanks, can defend an area of around 1km by 1km. So what can 21 battalions defend?

We need a strong mobilisation capability to be able to field this force and then expand it in time of real threat. One of the greatest bottlenecks in expansion is at the company commander level. They cannot be trained overnight. It takes a few years to do the job adequately. So men and women need to be recruited, trained and developed as commanders and then retained. Such a program is expensive and needs special consideration if it’s to be available in time of danger.

Our air defences need to be brought up to date. We require new fighters for controlling the airspace around Australia, and we need missiles and warning/control systems to support them. As we learned painfully in the Korean War, if you go into an air war with obsolete aircraft, you get knocked out of the skies. Any enemy launching an attack on Australia is likely to have impressive aircraft. The costs sound terrifying, but we shouldn’t fool ourselves—that’s the price of security in a developed East Asia. The same reasoning applies to transport and strike aircraft.

We’ve chosen in the more recent past to rest our hope for maritime security in a significant force of submarines. That strategy is still credible, so we need new submarines. We’ll also need more surface combatants to work with our submarine and air forces. We need supply vessels and both the Navy and the Air Force need newer base facilities. Clearly we’re moving into higher budget territory, and I would expect the White Paper to argue strongly for greater financial resources.

They won’t have an easy task in persuading the government, but they can point to the development of a potentially disorderly world around us to strengthen their leverage. The problem of controlling the flows of starving, badly-governed, desperate people is going to grow. Papua New Guinea has a population of nine million people, many of whom are subsistence farmers. When the effects of climate change become more evident it’s likely that there will be hundreds of thousands of hungry people looking for somewhere else to live.

There could be larger refugee flows out of the Middle East and Southeast Asia hoping to head in our direction. Conflict may occur in the East and South China seas. Kim Jong-un might use force against South Korea or Japanese interests. Europe has yet to absorb all the refugees that it has accepted recently, so there’s potential for turmoil within the borders of the European Union.

Those kinds of conflicts, including those in and around Russia, the Middle East and Africa, can create a climate of fear in the world, leading to severe breaches of the peace such as a terrorist group using a “dirty nuke” against a major US city. Such conflicts aren’t directed at Australia in the first instance but they can accelerate the growth of fear and violence which would have direct implications for Australia.

Those tasked with finalising the new Defence White Paper need to think widely, and those who allocate our national resources to security need to confront the questions of what kind of mobilisation base do we need and how can we make it effective in a timely manner if danger threatens.

Robert O’Neill is a Professor Emeritus of Strategic and Defence Studies at the ANU and a Fellow of the AIIA. This article originally appeared on The Strategist on 25 January. It is republished with permission.