Foreign media have noticed the president from the small Nordic country with 5.6 million inhabitants, often smiling in the front row in pictures from international gatherings where Ukraine is in focus. His growing importance in bringing Europe's – and Ukraine's – message to the US is causing some amazement.
In Finland, the media are speculating about whether Stubb can save Ukraine, and foreign media such as Politico have appointed him "Europe's special envoy for Trump".
Golf Diplomacy
As the first Nordic head of state, the 57-year-old triathlete and almost professional golfer visited Trump at his home course Mar-a-Lago in Florida in March and played a round.
You learn a person's personality after the first hole, Stubb states in an interview with Dagens Industri.
The day after the successful golf round – which the team won – Trump says he is angry with Putin and threatens new sanctions. A change in tone, which many attribute to the Finnish president's influence.
I hope the Kremlin understands that you don't play with President Trump, Stubb said.
Stubb himself tones down his importance in an interview with The New York Times. France's President Emmanuel Macron and Britain's Prime Minister Keir Starmer are leading the European effort, according to Stubb, who sees his own role as more of "pushing things in the right direction".
Finland as a Role Model
That Finland's president has taken a key role in supporting Ukraine and peace negotiations can be seen against the backdrop of the country's own experience of being attacked by Russia. At the end of the Winter War in 1940, Finland was forced to cede about ten percent of its territory to its neighbor, including Karelia, where the Stubb family has its roots.
Finland was forced to reduce its military capacity and become "neutral" to avoid provoking the Soviet Union's wrath, a fate that Stubb now wants Ukraine to avoid.
Stubb also has the advantage of not only being president but also commander-in-chief. Finland, with its exposed position, has built up a strong defense force, something that other NATO countries can learn from.
He has presented Finland as a role model in Europe when it comes to security policy, says Yle's correspondent for defense issues, Gustaf Antell, to Yle Arenan.
The Right Personality?
Stubb also has solid experience in foreign policy, both as foreign minister and as an EU parliamentarian, which is believed to have given him a realistic view of Russia.
And he has a personality that makes him seem like the person who maybe, possibly, can finally handle Trump, says Antell.