Merciless, bloody, rooted in a street-level explication of capitalism in its purest form, this war of the underworld would play itself out in many domains.
I think the author means "cutthroat competition," but easily uses "capitalism in its purest form" as an equivalent. I doubt that he had anything remotely like the capitalization of industries in mind. Even the more informal term free market seems out of place. What is "free" about a market that is run by violence and cronyism instead of price?
If we tease it apart further, I suspect Mr. English means "commerce not regulated by the government," and "a real risk of losing." Such criminally-dominated economies long predate any notion of capitalism or any writings of Adam Smith. These economies are actually quite common throughout history and worldwide. A more exact term would be "corruption."
I doubt that the author is intentionally trying to smuggle in any politics with this reference to capitalism. I think we can pretty well guess which way he might vote, if he votes at all, but scoring debating points on the sly is unlikely to be in his mind as he writes such things. He simply accepts these equivalences without much thought, as do his editors, and likely most of his friends. If the government isn't regulating the economy, and if someone can actually go bust, he sees it as capitalism. If the competition is severe and the government really doesn't have control, he sees it as "street-level explication of capitalism in its purest form."
A small thing, but an amazingly ignorant and biased one. Multiply it out by a thousand similar interpretations of anything to do with capitalism or the free market every day in the public discourse, and you can see why some folks would think government regulation is safe, and preferable.