Australia must decide if it will help the US in the event of a war with Russia to protect one of the Baltic states, global strategist Paul Dibb says.
Professor Dibb, an architect of Australia's military strategy from the 1980s, has just returned from Russia, warning that under -Vladimir Putin the country is seeking to reassert itself as a major power that could damage Australia's interests. 
"It seems set on a path to -confrontation with the West and is now challenging the established post-World War II security order in Europe," he says. In a paper to be released today by the Australian Strategic Policy Institute, Professor Dibb says Mr Putin claims the right to a sphere of -strategic interest in Russia's neighbourhood.
That sphere probably included Crimea and Ukraine but also the states of Belarus, the Baltic countries, Moldova and Kazakhstan.
Professor Dibb says Russia's rise, its ambition and its greatly increased military effectiveness has significant implications for Australia and the Asia-Pacific region.
"We need to consider carefully what our reaction would be in the event of major conflict in eastern Europe, provoked by Russia, which could involve our US ally defending one of the Baltic countries," he says.
Russia's refusal to act in ways consistent with international law and its "coercive and aggressive actions in Ukraine" are specifically criticised in the recent -defence white paper. Moscow was testing the -extended deterrence of the US and its ability to counter military coercion.
"How things work out in -Europe will affect Washington's ability to reassure allies and partners everywhere, including those in our region who must contend with increasing coercion by China," Professor Dibb says.
He says he is not arguing that Australia should earmark a force for possible combat in Europe if Russia attacked a NATO country. "But we do need to think through what our response would be, if any," he says.
Increased Russian -aggression could also divert US attention away from the rebalance to Asia-Pacific and embolden China in areas such as the South China Sea.
"Russia's aggressive military behaviour makes China's creeping and insidious incrementalism in places such as the South China Sea harder to counter because both Moscow and Beijing will be seen as getting away with it," -Professor Dibb says.Russia could give China -advanced technology, which would reduce the Australian Defence Force's technological edge.