He is heading into what would become the most destructive war the world had ever known.

How might he feel about what lies ahead? How would he justify travelling to the other side of the globe to kill or be killed?

What might his opinion be of the British Empire? Of his own country? Why is he even fighting? And how would he react to a vision of Australia in 2014?

Dr Craig Stockings, one of Australia's leading military historians and an academic at UNSW Canberra, has often considered how such a conversation might unfold. He believes it would be enormously surprising for many, mildly confronting for most and somewhat unsettling for modern-day Australians as a whole.

"The soldier would have a completely different world-view from today's Australian. He would likely seem racist, for example, and have ideas of what the Empire was, and what it represented, that would seem quite foreign a century later.

"He would also have ideas of what his nation is, and what it should be, that would stand in stark contrast to Australia of today," MrStockings says.

"He would most likely reject many of the defining characteristics of Australia in the 21st Century – its ethnic, cultural and religious pluralism for one – along with its move towards a truly independent nation.

"His Australia was a part of a greater whole, one he cherished. Where has Britain and all things British gone, he might ask. Where is the empire he sought to preserve and protect?  Many modern Australians forget we are not the same people as our forebears. They were different in countless ways."

And that is one important reason behind many misunderstandings of why Australians went to war in 1914. We mistakenly assume the people of the day were just like us but in different clothing, many historians say.

The false assumption that Australians had a modern-day attitude as opposed to an early-1900s mindset leads us to believe that Australians were fighting a war that was European and specifically British, a war that had little to do with Australia.

It is here from which the idea of marching to help Britain in World War I comes. Australians were not helping Britain. They were helping an Empire of which they were part, Stockings says. They were, in that sense, helping themselves. The modern division of identity between "us" and "them" did not exist in the early 20th century, as it does now.

Such thinking also leads us to consider the war as a wasteful tragedy for Australia, a pointless sacrifice of so many young lives. But a war that preserved and defended the empire was certainly not seen by Australians as a "waste" in 1914, or 1918 for that matter, Stockings says. And of course there is always the over-arching modern impression that any form of empire is a bad thing, and the wars of empire equally evil.

"Anything that is imperial or connected to the idea of empire is essentially a negative thing in our minds today, and I'm not saying that is entirely undeserved," Stockings says. "There are parts of the world that certainly didn't benefit from being part of a large, white, European empire.

"But the aftertaste is that empire is bad. This makes it harder for us to acknowledge or accept the idea that in the early 20th-century Australia was very much a willing and self-identified part of such an empire. Indeed, Empire Day was celebrated in Sydney and Melbourne before it was in London.

"That has very powerful and important connotations."

The formation of a feeling of nationalism comes when a group of people self-identify with each other, based on common history, traditions, laws and customs. Today, it could be said, Australians self-identify as an independent, autonomous and individualistic people from a geographically isolated nation who share a certain set of values, morals and ethics. We may come from around the globe, but we now share a meaningful bond and we are certainly not managed or influenced by people from distant lands.

But in 1914, the dominant nationalism was that of the Empire – not of Australia, Stockings says. There was no general sense of a separate nationalism, a separate group of people who thought of themselves as Australian as opposed to British. They were proudly Australian-Britons.

"If you feel that there was some sort of internal friction between being British and being Australian then you haven't got your head around what Australian nationalism meant in the early 1900s," says Stockings, the author of upcoming book Britannia's Shield : Lieutenant-General Sir Edward Hutton and Late-Victorian Imperial Defence.

"It was not just flag-waving and posters and God Save the King. There was a real self-identification with the Empire and an absolute understanding that we were a part of it.

"The fact that the Empire was at war in 1914 naturally meant Australia was at war. That was never questioned. It was a base assumption."

Understanding this fact means the loss of life becomes no less tragic; rather it might be said that the sacrifice becomes more honourable as it served a greater purpose. But feeling a sense of waste thanks to the idea that Australians were killed while fighting on the other side of the world in somebody else's war is absurd in a historical sense, Stockings says.

It once more ignores the Empire and is based on modern-day thinking about what this nation is in 2014, not what it was in 1914.

"The war was a world calamity," he says. "It was a disaster for civilisation. It was a huge and traumatic loss for Australia. But the idea of it as an unnecessary waste of life is after the fact.

"It is not considered that way in 1918. Indeed, many political and military elites across the Empire welcomed this war as a way of deciding the fate of empires. It was about sorting out the world order and many policymakers were not afraid of that.

"We have to replace this idea of fighting for Britain with the idea of fighting for Australia as part of the Empire. It is about facing up to the fact that this country was part of the Empire - and willingly so. Feelings of imperial nationalism at the turn of the century were stronger at the periphery than even at the centre. That was true of the other self-governing colonies, too."

Finally, if we take the reverse approach and ask what would the world and the balance of power look like had Germany been successful in World War I , we reveal yet another very good reason for Australia's involvement. There can be no question that local Australian interests were preserved through an Allied victory.

"It certainly would not have been to the benefit of the self-governing colonies in terms of their economies and trade and their place in the world," Stockings says.

"Even had there been some sense of a separate Australia, which there was not, it still would not have been in the national interest to allow things to unfold any other way."

So Australians were not coerced into joining the action and were not fighting somebody else's war. The fact is that there was no other choice, Stockings says. This is because the question of whether to fight or not simply never came up. Members of the Empire fought for the Empire.

There was no conscription in Australia during the First World War for overseas service because the Australian Imperial Force, in the early years at least, had no problems recruiting.

There was an anti-conscription movement later on, but that had less to do with an anti-war sentiment and more to do with a traditional aversion to compulsory overseas service.

It was a movement against the idea of forcing men to fight outside of Australia, not against the notion of conscription at home (which was actually in effect), and certainly not against the idea of fighting the war, Stockings says.

"Of course there were parts of the community across the Empire that did not feel an unfaltering commitment to the war," he says. "There were less than enthusiastic ethnic and sectarian groups, for example, but these were a very small fraction of the whole. The overwhelming majority did not question our involvement."

Australians joined in droves (by late 1915, more than 200,000 men had enlisted, and another 200,000 would join before the end of the war) for the same reasons that a Queenslander would sign up today if another nation attacked Western Australia, because their way of life was under threat and the people that shared a common sense of nationalism needed their help. The whole was under threat, so the parts reacted.

"To say that we were fighting somebody else's war is a nice catchphrase," Stockings says. "It is a neat way to capture things. But it is profoundly incorrect.

"It appeals to the heartstrings of modern-day Australian nationalism, but it is historically unsound."

"As the 20th century progressed, one dominant identity was gradually replaced by another. The risk, a century on, is to read history backwards and to insert modern meaning into historical situations. Many of us want to feel that there was a new Australian-ness that was trying to emerge from underneath the Empire's shackles from 1901, and that the new nation was somehow held down, or exploited by the empire.

"As an idea it is cute, but it is simply not true."

And so, if the soldier from 1914 was introduced to the Australia of today with its sense of independence, its multiculturalism, its localised nationalism and its strong affinity with its Asian neighbours and the United States, then, yes, he may finally step back and wonder why on earth he had signed up. But at the time it made absolute sense - it was an empire state of mind."

* This article was commissioned by UNSW Canberra, the Canberra campus of UNSW at the Australian Defence Force Academy. During the Centenary celebration period, UNSW Canberra will focus not only on World War I, but commemorate more than a century of service in other conflicts by Australian servicemen and women.