On one side was the German chancellor, fresh from stage-managing her planned departure after 13 years in power; on the other was Australia’s fifth prime minister in five years, who only took over in August after a brutal leadership coup ousted his predecessor.

Little wonder, then, that Angela Merkel resorted to a cheat sheet to catch up about Scott Morrison when the two met for a short bilateral at the G20 summit in Buenos Aires at the weekend.

G20 summits, much like UN general assemblies, represent a form of diplomatic speed dating, although normally world leaders have got the basic biographical details of their fellow world leaders in their head.

But Merkel, the personification of continuity in politics, openly stared at a guide to Morrison complete with an identifying photograph, before offering praise to his rightwing coalition government. She also repeatedly consulted her watch during their meeting.

Angela Merkel checks notes with information about her counterpart. Photograph: Lukas Coch/AAP

Such is the febrile nature of politics in Australia, where parties of of left and right appear almost addicted to political assassination, there is every chance that Morrison will have exited the international stage by the time of the next G20 summit in Tokyo.

Polling for elections next year point to victory for the opposition Labor party, currently led by Bill Shorten, which would require the German diplomatic service to furnish Merkel with a new guide.

In an attempt to end the cycle of political revenge, and the international image of instability, Morrison’s Liberal party called a late-night meeting on Monday to try to force through a rule change that would make it more difficult for a party leader to be ousted. The party insisted the move was not in response to Morrison’s international anonymity.

The Australian Labor party changed its rules five years ago after it experienced a similar outbreak of leadership defenestrations. Julia Gillard ousted Kevin Rudd in 2010, and three years later Rudd dispatched Gillard. He then introduced a rule that meant MPs and party members would need to vote before a leadership change.

Merkel can hardly blame a lack of preparation time for her ignorance of Morrison. A glitch with her plane meant she arrived eight hours late, giving her more inflight time to study Morrison’s biography. The real worry for Australia is that operating on the principle that “there will be another one along in a minute”, Merkel simply couldn’t be bothered.