Russia could be pulling its cyber punches against Ukraine despite targeting civilian infrastructure over fears of sparking NATO involvement.
Retired US army major general John Davis says the use of cyber attacks are less effective once war breaks out, given the uncertainty in the online realm.
"Why rely on something where the probability of success or precise impact is less certain ... when you can bomb it or shoot it with much more certainty," he told the National Press Club in Canberra on Thursday.
The retired general said Russia may have stopped wide-ranging cyber attacks over fears about what would draw NATO involvement after a conflict has already broken out.
"Russia's decision makers are less certain about what actions might draw a more direct confrontation with NATO," he said.
"They did not use capabilities designed to spread uncontrollably beyond the targets."
Mr Davis added that Western nations needed to be more transparent about cyber operations in peace time to avoid unintended consequences.
"If we're going to go to war with an adversary nation, this should be an intentional decision, not a mistake," he said.
Russia is continuing to take out civilian and power infrastructure in Ukraine as winter encroaches, with temperatures already dipping below freezing.
Ukraine's ambassador to Australia Vasyl Myroshnychenko said it was unacceptable that Russia is "making life unbearable for the civilians."
Defence Minister Richard Marles has pledged Australia's continuing support for Ukraine.
"Our position in relation to Ukraine and the war in Ukraine has not changed," he told reporters on Thursday.
"What we're seeing is unprovoked aggression from Russia.
"It cannot be allowed to stand, that's why we will be supporting Ukraine for as long as it takes for Ukraine to ultimately end this war on its own terms."
NATO and Poland have concluded that a rogue missile that struck the nation, killing two civilians, was unintentional and likely from a Ukrainian air defence system.
But Western nations have still put the blame at Russia's feet.
US ambassador to the United Nations Linda Thomas-Greenfield said Ukraine had every right to defend itself.
"This tragedy would never have happened but for Russia's needless invasion of Ukraine and its recent missile assaults against Ukraine's civilian infrastructure," she told the UN Security Council.
Ukrainian President Volodymyr Zelenskiy has called for access to the site for further investigation after initially stating the missile was Russian-made.
The US says it has no reason to contradict Poland's preliminary findings.