Ron Dennis has explained his decision to block McLaren's engine partner Honda from supplying a power unit to Formula 1 rival Red Bull next year.
Having wanted to pull out of its contract with Renault a year ahead of schedule, Red Bull turned to Honda after Mercedes and Ferrari both decided against stepping into the breach for 2016.
But with Honda and McLaren Technology Group CEO Dennis both needing to be in agreement on the matter, it was the latter who ultimately made the call, but only after the Japanese manufacturer also recognised the likely difficulties.
On his first visit to a race for two months ahead of Sunday's Abu Dhabi Grand Prix, Dennis explained: "We sat with Honda and absolutely analysed where we were, and whether it would enhance our ability to move even faster, or not, whether supplying another team like Red Bull would pressurise the system even more.
"Based upon the current supply structure, where we are with the engine, the time before the first grand prix, it was very, very clear it was not physically possible to push the suppliers up the supply chain to increase production because we didn't know what we wanted them to make.
"Our engine programme will be enhanced next year because we want to take the maximum amount of time to make parts.
"How many parts you make, bearing in mind there is a lot more freedom now, the more engines you have to make, the more your supply chain gets stressed.
"Having increased the budget into Formula 1, Honda could see no economic logic at this stage to embrace another team.
"But someone had to take a clear decision, and so I took one, and therefore took the understandable flak.
"It was fully supported by Honda that we didn't have the capacity to engage another team, but someone had to stand up and say 'this is not going to happen'.
"This wasn't me countering a desire of Honda, this was me taking responsibility for a decision, which goes with the job."
FIA president Jean Todt recently suggested motorsport's governing body would try to impose a new rule whereby a power unit manufacturer would have to supply a minimum of two teams.
While the FIA wants manufacturers to put together a proposal including details on how to "guarantee the supply of power units to teams", Dennis has hinted at the problems that could lie ahead.
"We were party to the discussions last week," said Dennis, with reference to the talks that unfolded during the F1 Commission meeting.
"It's different if the regulations are changed, then everybody can start from the same position and react accordingly.
"We're in catch-up mode, in a period where the powertrain can be monstrously complex, and you can't react quickly enough because some of the suppliers are not geared for Formula 1 pace.
"The more people you have to carry with you the slower your reaction time.
"To slow down our own ability to become competitive didn't make any sense."