The lesson of history is that vigilance must be eternal

Australia's involvement in World War I is defined and remembered by the heroism and sacrifice of our troops at Gallipoli.

While many Australians also fought on the battlefields of France and elsewhere, which is recognised and recorded, it is the Gallipoli campaign that captured the imagination of the Australian public and gave rise to the ANZAC legend.

Similarly in World War II, the trials and tribulations of our diggers trudging along the famed KokodaTrack, magnificently assisted by the people of Papua New Guinea, have inspired thousands of Australians in recent years, paying tribute to their heroism by walking the same trail.

It is intriguing that the only large-scale attack on Australian soil during World War II has not, until recently, featured prominently in our embrace of Australian military history.

The initial bombing of Darwin by the Japanese airforce on 19 February 1942 was the largest attack on the Allies following the December 1941 bombing of Pearl Harbour.

The raids on Darwin by 242 Japanese planes caused enormous damage to military and civilian targets.

While the first wave of planes focused on military targets of ships and airstrips, communications infrastructure such as the telegraph and post offices were also destroyed.

This attack lasted about 40 minutes with a second wave of planes an hour later targeting the Air Force base.

Darwin’s only defence was 10 fighter planes - nine of which were destroyed during the first attack.

Eight ships in the harbour were sunk with significant damage to numerous other vessels.

The US naval destroyer USS Peary was hit with five bombs and 91 crew went down with the ship.

The two attacks that day caused the deaths of 243 people, with than 400 people suffering wounds and injury.

Regular air attacks on Darwin continued until November 1943, with 64 raids on Darwin and 33 on other places in Northern Australia including Townsville, Derby and Port Hedland.

The death toll from these attacks reached more than 900 people, with numerous ships and almost 80 aircraft destroyed.

It is estimated that the Japanese airforce lost more than 130 planes during these raids.

At that time there was great fear in Australia that the Japanese bombing was preparing the way for a ground invasion.

Japan had officially entered World War II in December 1941 and quickly achieved a number of decisive victories including at Singapore only a few days prior to the first attack on Darwin.

Australia's northern defences were quickly bolstered to prevent such an invasion.

These defensive measures included a large increase in the numbers of troops stationed in the city.

Soldier numbers peaked at 110,000 in 1943.

My father Douglas Bishop was among those who served in the AIF in Darwin during the war.

He returned to Darwin this week to attend the Bombing of Darwin memorial services honouring those who had served and those who had lost their lives.

It was the first time he had attended these ceremonies to mark what is now an annual day of observance.

Like many of the former servicemen and women in attendance, he found it an emotional experience.

While an estimated one million Australian men and women served during World War II in Europe, Africa, Asia and the Pacific, with 39,649 killed and tens of thousands seriously wounded, the bombing of Darwin is significant.

It was the first attack by a foreign power on Australian soil and it represented the first serious threat of invasion by a foreign army.

It is clear from historical records that Australia was caught relatively unprepared for the Darwin attack.

After the devastation of World War 1, successive governments failed to invest sufficiently in our defence capability while coping with the ravages of the Great Depression.

In his book The Government and the People 1939–1941, Sir Paul Hasluck observed that:

It was true that the 1938- 39 figure was nearly twice as much as Australia had ever spent in a single year and four times as much as she had been spending five years earlier, but it was a tiny proportion of the nation's resources and the dangers were great and so immediate.

Perhaps more than anything else the modesty of the defence proposals at this period was due to a defect, not of the will but of the imagination.

The lessons from history are that threats can emerge more quickly than anticipated and it is prudent to maintain an appropriate level of preparedness at all times.

That is what makes so concerning the decision of the Labor Government to cut defence spending as a percentage of GDP to its lowest levels since 1938.

While there is no obvious threat on our horizon, even a cursory study of our own history will show how quickly the security situation can change.

The famous quote (of disputed origins) that "Eternal vigilance is the price of liberty" should never be ignored.