Stellantis was formed in 2021 to create a powerful business machine out of two weaker ones but the rationale behind that move is looking shaky these days. What is the case for keeping it together?

When FCA and the PSA Group merged, the US and Europe were heading in roughly the same direction in terms of reducing vehicle emissions. But now the US has dismantled those regulations and erected trade barriers. With that, the bloodstream connecting Stellantis's twin heartlands is slowing to a mere dribble.

Only Jeep is shared between the two markets at any scale, but in reality it has essentially become two brands, one American and one European. Even the new Italian-built Compass won't be exported to the US because of tariffs. So where are the efficiencies now?

The US side of Stellantis always complained that it was starved of investment in favour of the European side, but that's no longer the case. In October last year, Stellantis announced a $13 billion US investment, focusing on pick-up trucks, large SUVs and powerful combustion engines.

Free of green obligations, Stellantis cancelled all its US-market plug-in hybrids for 2026. Regular hybrids and range-extenders are still in development, it says, but the pressure is minimal.

For the former American 'big three', these are "near-optimal conditions" in which to operate, according to one banking analyst: sell lots of high-margin trucks and rake in the money.

Stellantis and FCA before it have always been run in cash-extractive fashion, almost like a private equity company. For any investor, hiving off Stellantis's US operations might look very appealing for a short-term gain. General Motors is essentially a US-only firm right now and is doing very nicely. The minimal overlap between Stellantis's brands would make it very easy.

Stellantis's European side, meanwhile, might be forgiven for feeling like the unfavoured child now. In the firing line from regulations, Chinese competition and under-performing brands, it has to watch while the US gets all the attention.

The latest blow is news that Stellantis will host its latest strategic plan presentation on 21 May in Michigan, not Europe.

In a book published after his departure, founding CEO Carlos Tavares wrote that he feared a split with the firm's French interests no longer defended. His prediction could yet come true.