The New Zealand delegation first flew to London for a meeting of Commonwealth leaders, where Fraser also met the King and attended Churchill's War Cabinet.
Then it was on to the main event. A historic conference in San Francisco to establish the United Nations.
With the war in its final stages, it was a dramatic moment. The world's newspapers split their reporting between developments in San Francisco and the race for Berlin.
Fraser played an outsized role at the conference. His diplomatic skills and forceful oratory afforded him influence well beyond what was expected for such a small nation.
He rallied opposition against proposed veto powers for permanent members of the new Security Council. He pushed for full employment to be included in the UN Charter, arguing that when it came to preventing conflict, economic prosperity mattered as much as any military pact.
And he chaired the committee establishing the UN's trusteeship system, laying a path for the independence of more than a dozen countries, including Samoa.
Jacinda Ardern's arrival at the UN last weekend followed a familiar route. Her itinerary also began in London, meeting the British Prime Minister and the King.
With a war in Europe and the threat of a major power using nuclear weapons, Fraser's legacy can't have been far from her mind.
After five years, she has earned a reputation as an international stateswoman and is instantly recognisable to millions.
Judging by her address to the UN General Assembly, she believes there is no point in having that reputation if you are not prepared to use it.
Ardern wasted no time linking the failure of the Security Council to act following Russia's invasion of Ukraine to the need for reform.
Russia's use of the veto to block UN action is exactly the problem Fraser foresaw in 1945: create a veto power and it will be abused.
That is why New Zealand backed a key change in April. In future, any use of the veto will trigger a session of the entire General Assembly where the member state in question will be asked to explain themselves.
Ardern wasn't alone in pushing for change. US President Joe Biden called for veto powers to be used only in "rare, extraordinary situations".
Her strong stance against Russia did not go unnoticed. Ardern was one of only a handful of leaders to secure a bilateral meeting with the Ukrainian Prime Minister.
And she continued to walk the talk on her response to the March 15 attacks, announcing the next phase of the Christchurch Call initiative with French President Emmanuel Macron.
Like Fraser, Ardern felt the dull thud of domestic political reality upon her return.
By Tuesday she was back fronting questions in Parliament and being asked by the media what she thought of comments by niche broadcaster Sean Plunket. Thud.
But the Labour leader can take some comfort in what happens next in Fraser's story.
Just over a year after San Francisco, Labour were narrowly re-elected in 1946.
Not a bad achievement given the rocky global economy, ongoing war restrictions, and a resurgent National Party under Sid Holland.
While it must have been tempting to demand another term as a reward for his wartime leadership, Fraser's masterstroke was to steer the election away from being a referendum on the past to a choice about the future.
A useful lesson from the first Labour government to the sixth.
Andrew Kirton was Labour's General Secretary from 2016-2018. He now works in government relations for transtasman firm Anacta Consulting. He is married to a Labour MP.
