A fourth Australian prime minister in five years gives the impression of constant political turbulence. But while Malcolm Turnbull's ousting of Tony Abbott for the leadership of the Liberal Party reflects divisions within the dominant grouping in the ruling coalition government, the key areas of foreign and international economic policies and national security will for now remain consistent. Staging a coup is only half the battle, after all; before there can be any changed outlook, the new leader has to bring about unity. It is to be hoped he succeeds; the nation and region need the moderate views and streak of realism that were so absent in his predecessor.

Turnbull, a former investment banker, lawyer and journalist, is Australia's most popular politician. His forward-looking views on issues like climate change, gay marriage, republicanism and immigration put him at odds with Abbott. That difference has given him a popularity beyond his conservative party to supporters of opposition political groups. But his leadership victory, by 54 votes to 44, shows hardliners remain a formidable force within his party.

Business sentiment is high after his win. So, too, are hopes among environmentalists that Australia will again adopt a responsible approach towards global warming. Foreign Minister Julie Bishop retains her post, but the new leader's belief in conciliation marks a shift in approach towards China and key ally the US. An immediate challenge is winning approval in the upper house of parliament, where the coalition lacks a majority, for the free-trade pact with China, seen by the Labor Party opposition and unionists as a threat to jobs.