Although loyalty has always been the coin of the realm in Trumpworld, White House staffers’ fealty to Donald Trump might soon be tested. Already, the legal fees are likely piling up for the growing list of Trump aides and associates whom special counsel Robert Mueller intends to interview; in the past week alone, White House Communications Director Hope Hicks, White House counsel Don McGahn, and former chief of staff Reince Priebus have all hired attorneys to represent them as the F.B.I. investigation into Russian interference in the 2016 election expands. Trump, Jared Kushner, Paul Manafort, Mike Pence, Michael Cohen, and virtually everyone else with exposure to the Russian scandal are all lawyered up, too, and with good reason: as Axios reported Tuesday, White House allies believe that Mueller is zeroing in on Trump’s dismissal of F.B.I. director James Comey in May, which has reportedly spurred what appears to be an obstruction of justice case against the president. On Sunday, former White House chief strategist Steve Bannon called Trump’s decision to fire Comey, who was then overseeing the Russia probe, the worst mistake in “modern political history.”

That mistake looks more disastrous with each passing day. According to Axios’s Mike Allen and Jonathan Swan, aides with legal exposure are particularly concerned that Mueller is focusing on an early draft explaining Trump’s reasoning for dismissing Comey, which was never released. Instead, the White House published a recommendation penned by Deputy Attorney General Rod Rosenstein blaming Comey’s handling of the Clinton e-mail investigation for his ouster. But Mueller has the original “screed”, revealing the president’s thinking and giving him leverage as he investigates potential efforts to obstruct justice. Others are reportedly worried that Mueller’s probe has expanded to include unrelated financial crimes involving the Trump Organization and alleged connections to Russian money laundering.

While Trump’s aides and associates have varying levels of exposure to legal risk, experts suggest that Mueller will be eager to use the threat of perjury charges to extract information, forcing allies to tread a precarious—and expensive—path. Mueller and congressional investigators are already preparing to question a number of current and former high-ranking Trump aides, including Hicks, Priebus, and former press secretary Sean Spicer, among others. As I reported earlier this year, White House aides likely to face legal fees that range as high as $1,000 an hour. The Daily Beast reported last week that there is an effort underway to organize a legal defense fund for staffers.

While it is widely accepted within the legal community that a sitting president cannot be indicted, White House staffers are not immune and face a considerable risk of accusations of obstruction of justice or perjury. “That is the real danger for people,” William Jeffress, the attorney who represented I. Lewis “Scooter” Libby in the Plame Affair, told me earlier this year. “You see it time and again in these political investigations, that they wind up, whatever happened wasn’t a crime. It may have been a political scandal—but it wasn’t a crime—but they charged somebody with perjury or obstruction. So that is the risk for everybody.” Libby, for instance, was not charged with any crimes related to the leak of former C.I.A. operative Valerie Plame’s identity but went down on charges of perjury and obstruction.

Facing this risk, White House staffers could confront a legal quandary in the coming months: choosing between Trump and criminal charges. “The lesson to be always learned is loyalty is one thing, but are you prepared to go to jail for it?” former Whitewater special counsel Robert Ray, told Politico. “A lot of young people go to the White House and they’re going to be loyal to the president and the president is going to be loyal to me. Bullshit. If it’s expedient, you’re going to be thrown under the bus. The loyalty isn’t necessarily going to be returned. Even if it were, I’m not sure the promise or prospect of a pardon is all that comforting.”

Last month, Trump faced a fresh wave of criticism when he pardoned Arizona Sheriff Joe Arpaio. For staffers worried that they might soon come under scrutiny in Mueller’s investigation, the controversial decision may have assuaged some of their fears. But the news that Mueller has teamed up with New York Attorney General Eric Schneiderman in investigating Manafort should give them pause. Trump’s presidential pardon powers only apply to federal crimes. And if state attorneys general like Schneiderman bring charges against them, not even Trump will be able to protect them.