The once monolithic automotive industry is splintering over a range of issues, as companies scramble to cope with unprecedented technological disruption and business challenges.

The big picture: Although fiercely competitive in the showroom, automakers have long presented a united front on shared interests like trade policy, government regulations and labor relations. That's all gone out the window lately; now it's every man for himself.

What's happening: General Motors' unprecedented racketeering lawsuit this week against Fiat Chrysler Automobiles is the latest example of automakers turning on one another.

GM accuses its crosstown rival of inflicting billions of dollars in damages by bribing United Automobile Workers leaders for competitive advantages that the union denied to GM.

They say the injuries compounded between 2009 and 2015 in the form of higher labor costs and lost investment initiatives.

GM said former FCA CEO Sergio Marchionne, who died in 2018, conspired with former UAW president Dennis Williams to try to weaken GM and force it into a merger with FCA in 2015.

FCA vigorously denies the charges, and says GM is trying to undermine current merger negotiations with Peugeot parent Groupe PSA and ongoing labor talks with the UAW.

"If arguments both sides are making against each other are true — that Marchionne was using the UAW to bully GM's Mary Barra, and that she's now trying to undercut Fiat Chrysler's combination with PSA — the chess moves will go down as among the most dramatic by Detroit executives in decades, " writes Bloomberg.

writes Bloomberg. On Thursday, JPMorgan analysts estimated that GM is likely to seek at least $6 billion in damages, and as much as $15 billion.

Another big split occurred recently in the war over tailpipe emissions rules.

Ford, Volkswagen, BMW and Honda have lined up behind California, whose right to set its own pollution standards was revoked by the Trump administration.

GM, FCA, Toyota and others, meanwhile, are siding with Trump, who wants to roll back tough Obama-era standards.

Where they line up depends mostly on their sunk investments in future powertrains and how they think consumer demand will evolve.

Two decades ago, Detroit automakers fought shoulder-to-shoulder against California's clean car initiatives.

What to watch: Shifts in trade policy could further divide the industry as the interests of foreign and domestic automakers diverge.

The bottom line: Faced with falling global sales and a potential transformation of the business, "the always-competitive auto industry has become even more dog-eat-dog," says Cox Automotive analyst Michelle Krebs.

Go deeper: