It is all about fear. Many Labor supporters, although buoyed by the opposition's lead in the polls, now worry that community fears of Chinese expansionism and the Russian invasion of Ukraine will combine to save the government's skin at the next election.

The term "khaki election" conjures up images of troop deployments and other military operations. But khaki elections can be about cold wars as well as hot wars, and are as much about states of mind as states of war. They are most effective when the other side of politics, usually Labor in the Australian context, can be portrayed as weak in the face of an international threat.

The history of national security politics in Australia includes the portrayal by the Menzies government of Labor as "soft on communism" during the 1950s. The portrayal equated socialism and communism, and was built on a mixture of international and domestic fears of communist influence. Trade union politics and alleged Labor links with the Communist Party of Australia were part of the mix. The era included the Petrov Affair prior to the 1954 election, the Labor split, and the emergence of the anti-communist Democratic Labour Party. It was all one part of a winning recipe.

The potency of "reds under the bed" slowly eased despite the Vietnam War, but even in 1972 Gough Whitlam could be derided as "the Manchurian candidate" because of his visit to China as opposition leader.

In 2001, national security was linked by John Howard to border security during the Tampa affair, and more traditional threats of war following the 9/11 attacks. Commitment to the US alliance has also been a regular element of the campaign mix.

Now we have attacks by the Coalition government on Labor and its leaders, Anthony Albanese and Richard Marles, which have eerie echoes of all the different meanings of past khaki elections and reds under the bed.

Led by Defence Minister Peter Dutton and echoed by Prime Minister Scott Morrison, they have focused on Chinese expansionism and support for Putin's Russia.

These attacks have run the full gamut from allegations that Labor is soft, weak and/or misguided on China to personal attacks labelling Albanese or Marles as "Manchurian candidates", the Chinese pick for the coming federal election, and even, most outrageously, Chinese agents.

In the right circumstances, such confected allegations can be potent. Incumbents have all the levers of government to pull in terms of decision-making, grand gestures and addresses to the nation, and denunciations of foreign threats always evoke fear.

National security campaigns also suck the air out of other issues, including those most on the mind of the electorate. Try to gain media attention during an invasion for a speech on the manufacturing industry, like the shadow treasurer, Jim Chalmers, has tried, and you will get the point.

Finally, if the electorate is fearful enough of war - or unsettled enough by communist expansionism - some voters may actually be driven to change their minds at the ballot box. But timing is relevant, and the election is still many weeks way. A lot can change.

The reliability of the opposition leadership is also a factor. It must sit tight and demonstrate its credentials.