On Wednesday, Honda announced that it would rejoin F1 as a full power unit manufacturer for the Aston Martin team, coming on board in 2026 when F1 introduces a new engine formula.
Martin Whitmarsh, Group CEO of Aston Martin Performance Technologies, explained that the Silverstone team had to become independent to achieve sustained success, moving away from a reliance on its current engine and gearbox supplier Mercedes, from which it also rents a wind tunnel.
"It's clear to us and I think to Honda that the 2026 Formula 1 regulations will require the sort of full integration of chassis and power unit that only a full works team relationship delivers," he said.
"If you want to win, it means beating Mercedes and it's extremely difficult to beat an organisation as good as Mercedes if you're reliant on them for intellectual property, facilities, components, so in my view, it is very, very difficult to win consistently championships without a full works relationship."
But while Alonso shares Whitmarsh's enthusiasm for the Japanese giant's arrival, he replied "no" when asked if Aston needs a works engine to win a world title.
He says the wait for Honda doesn't mean Aston Martin can't win championships over the next two seasons.
"Especially in 2026 when the new revelations will come, it is always better if you can develop your power unit together with the chassis and have everything integrated well in advance," he said.
"Being a works team there are only benefits, but that doesn't mean that until 2026 Aston Martin will not have a chance to win the championship."
According to Alonso, attracting Honda is the latest coup that highlights the Lawrence Stroll-led team's ambition. Aston is set to move into a brand-new, state-of-the-art factory in Silverstone and it is also building a new wind tunnel.
"It's very good news for the team. Very excited. I think it shows the commitment of Aston Martin to really win races, win championships in the future being independent, manufacturing their own gearboxes and everything on the car.
"It's the only way probably, to really be 100% sure that you are in control of everything in your package, in your car. And it's a great sign for everybody in Aston Martin. You know that the desire and the potential to win is there."
Alonso will be 44 at the start of the 2026 season but has batted away questions on whether or not he will still be there when Honda joins.
"I don't know what I will do in 2026," he said. "I would lie if I told you that I know right now.
"It's way too far ahead to really have an idea, so I have to concentrate and focus on this year."