Shortly after Russian-backed rebels downed Malaysia Airlines Flight MH17 over Ukraine in July 2014, Australia, which lost 27 of its nationals in that crash, hosted the Group of 20 summit in Brisbane. Then Australian Prime Minister Tony Abbott vowed to "shirt-front" Mr Vladimir Putin about the downed plane while his diplomats secretly wished the Russian leader would find some excuse to stay away.

Mr Putin not only showed up, affecting insouciance, but also sent a flotilla of Russian warships off north-eastern Australia for good measure. Moscow said the four vessels, led by the cruiser Varyag that is equipped with nuclear-tipped missiles, were testing their range capability in case they had to do climate change research in the Antarctic.