WASHINGTON — When Anthony Scaramucci, the new White House communications director, went on television on Thursday morning to compare himself and his adversary, Reince Priebus, the chief of staff, to Cain and Abel, it seemed to encapsulate the fratricidal nature of an administration riven by biblical rivalries. Cain, after all, killed Abel as they vied for God’s favor.

As it turned out, that was the cleaned-up version. In a vulgarity-laced telephone call with a New Yorker writer reported on the magazine’s website on Thursday evening, Mr. Scaramucci railed against Mr. Priebus and Stephen K. Bannon, the president’s chief strategist, both of whom opposed his hiring last week. He even vowed to get the chief of staff fired. “Reince Priebus — if you want to leak something — he’ll be asked to resign very shortly,” Mr. Scaramucci said.

Whether Mr. Scaramucci will turn out to be Cain or Abel, it was clear that his appointment has added another layer of drama and dissent to a White House suffused in it — and revived the perpetual questions about Mr. Priebus’s fate. Sean Spicer, the White House press secretary and an ally of Mr. Priebus, resigned in protest when Mr. Scaramucci was hired last week because, he predicted, it would only add more chaos to the team. On that, at least, he seems to have been proved right.

But President Trump not only tolerates feuds within his team, he fuels them, playing one courtier off another and leaving them all unsteady. He chooses favorites and casts others aside, but even those decisions seem subject to change at any moody moment. And by several accounts, he personally encouraged Mr. Scaramucci’s jihad against Mr. Priebus, once again subjecting his chief of staff to a ritualistic public lashing even as he considered pushing him out.