What price abroad for Australia's latest leadership upheaval?

Australia has done it again. For the fourth time in a row, a serving prime minister has been deposed in an intraparty battle without completing a full election term.

Mr Malcolm Turnbull, who usurped Mr Tony Abbott as prime minister in September 2015, became the usurped last week, yielding the top job and Liberal Party leadership to Treasurer Scott Morrison.

Triggered by a failed but fatal leadership challenge by Home Minister Peter Dutton, Mr Turnbull's ignominious dethroning capped a tumultuous few days, even by the standards of previous putsches. As political theatre, it was enthralling, but did nothing to dignify the democratic process.

While this latest leadership decapitation has prompted popular anger, it was conducted consistently within party rules. It does not feel like a political crisis. Australia's political institutions remain robust and accountability to the electorate will surely come at the next federal election, which has to be held by next May.

Nonetheless, the quasi-normalisation of political regicide as the mode by which prime ministers enter and leave office in Australia suggests structural redress is required.

Introducing fixed terms and lengthening election cycles from four to three years would help. Canberra's brand of Westminster-based democracy is not existentially threatened. But Australia's credentials in democracy promotion are undermined by such persistent dysfunction.

The current crop of career politicians appear oblivious to this as a cost to Australia's international standing and diplomatic defence of the "rules-based order". It is not clear where the courage for political reform will come from, but it is badly needed.

FOREIGN RELATIONS FALLOUT

What are the more immediate implications of the change in leadership for Canberra's diplomatic engagement with the region? Does it impact Australia's foreign policy in other ways, beyond devaluing the "democratic brand"?

The Liberal Party coup against Mr Turnbull was ideological in nature, led by those who strongly disliked his progressive tendencies. They want a more conservative approach.

This does not obviously impinge on foreign policy, except in the area of climate change. Mr Morrison, himself, is no ideologue and likely to adopt a pragmatic, continuity-based approach abroad.

The new PM's key problem is limited bandwidth, as his government's overwhelming priority in the coming weeks is to restore party unity, to defend the coalition's wafer-thin majority and forestall an early election that they are at high risk of losing.

Mr Morrison's immediate preoccupation is survival, in other words. A Cabinet reshuffle will follow quickly. Ms Julie Bishop, who polled poorly in her own bid for the Liberal Party leadership, has announced her resignation as foreign minister.

With her departure, Australia's diplomacy will inevitably enter a holding pattern while her successor, Ms Marise Payne, grapples with the usual demands of a new job. The most competent senior officials can do no more than hold the line without ministerial direction.

In truth, there is more angst within Australian foreign-policy circles about the Liberal leadership upheaval than in the region itself. Australia's unscripted executive changeovers are already priced in, just as they used to be in Japan before Mr Shinzo Abe came along.

DANGERS OF AN EMPTY CHAIR

Still, leadership continuity is highly prized in Asia, where high-level diplomacy is conducted on an interpersonal level. Showing up counts. To his credit, Mr Turnbull invested capital in strengthening Australia's relationships in South-east Asia, particularly during the second half of his term.

Under his watch, Australia not only hosted the first Asean leaders summit, but also firmed up bilateral strategic ties with Singapore, Vietnam and the Philippines, while laying the ground for a rapprochement with Timor Leste.

It is doubtful whether Mr Morrison's administration can maintain the same momentum, given the need for front-bench substitutions and its overwhelming inward focus.

The Prime Minister was scheduled to visit South-east Asian countries this week, ahead of the Pacific Islands Forum (PIF), in Nauru. It is especially bad timing that the leadership change coincided with back-to-back visits to Australia's most important near regions. This is where Australian diplomacy and leadership counts most, where the impact of non-attendance or downgraded representation will be felt most keenly.

An empty leader's chair at the PIF would be especially damaging, given that the point of Canberra's policy "step up" in the Pacific is designed to demonstrate momentum behind Australia's renewed commitment to the region and to counter perceptions that it has lost influence there.

Australia is again the butt of jokes about being a failed state in the South Pacific. With each successive political assassination, this gets harder to laugh off.

INDONESIA AND CHINA

One proximate policy challenge in South-east Asia is to see through an Indonesia-Australia free trade agreement (FTA) to conclusion.

A draft agreement was to have been the main deliverable from Mr Turnbull's visit to Jakarta. A bilateral FTA with Indonesia is a big prize, one that would additionally demonstrate Australia's ability to economically diversify beyond dependence on China, laying firmer foundations for Australia's see-saw inter-governmental partnership.

Reports over the weekend suggest that Mr Morrison will travel to Jakarta this week. If so, that is encouraging sign of commitment to a foreign policy agenda at such an early stage. It will do the Prime Minister's reputation at home no harm if he can bag an early foreign policy win.

But he will quickly learn that foreign policy is more than a matter of choice. China will make unsolicited demands on his diplomatic skills and attention span.

After a long period of strain, there have been signs of an incipient thaw. For the first time, China's navy is set to participate in a naval exercise hosted off Darwin later this week.

Mr Morrison's final act as Treasurer, announced the day he became Prime Minister, was to exclude China's Huawei from participating in Australia's future 5G communications network. Beijing is likely to retaliate.

Mr Morrison will hope that appointing a new foreign minister helps to reset the relationship with China. But there could be an icy baptism for Ms Bishop's successor, regardless.

Just over the horizon, Papua New Guinea is hosting the Asia-Pacific Economic Cooperation Summit in November.

This will probably be Mr Morrison's first major appearance on the multilateral stage, including possible side visits to Australia by Mr Abe, US President Donald Trump and South Korea's President Moon Jae-in. That is plenty for Australia's new PM to get up to speed on beyond the domestic questions in hand.

The more sobering question, for Mr Morrison's and Australia's diplomacy alike, is this: How seriously should foreign leaders treat him, as Australia's fifth prime minister in as many years, with perhaps no more than a few months in office?