Michael Wolff has a new book out, and Donald Trump is not a fan. The US president’s legal team sent cease-and-desist letters to Wolff and his US publisher, Macmillan imprint Henry Holt & Co., in response to the new book Fire and Fury: Inside the Trump White House. In the politest terms, it paints an unflattering picture of the Trump administration’s first year in office.

The letter calls on Henry Holt to halt distribution of the book, publication of which was originally set for Jan. 9 and has now been pushed up to Jan. 5. Trump’s team alleges that the book is libelous to the president—probably because it makes heavy implications about the his mental health. The president’s attorney, Charles J. Harder, sent a similar letter to former White House strategist Steve Bannon, whose quotes are peppered throughout the book—most notably a comment on a now-notorious meeting between a Russian lawyer and Donald Trump Jr. during the 2016 presidential campaign. “Even if you thought that this was not treasonous, or unpatriotic, or bad shit, and I happen to think it’s all of that,” Bannon purportedly told Wolff, “you should have called the FBI immediately.”

It’s not surprising that Trump would be upset by the book. But he’s a public figure—and so, in court, he would need to clear a much higher bar than a private citizen to prove defamation by libel. The question now is whether Trump would actually want to take Wolff, Bannon, and Wolff’s publisher to court—and what would happen if he did.

In order to win a libel lawsuit against Wolff and Henry Holt, Trump would need to prove that a damaging claim in the book was written with “actual malice”—that is, that Wolff and the publisher must have had knowledge of its falseness, or have acted with reckless disregard for the truth. It’s not enough to prove the falseness of the claim alone, or the subsequent reputational damage wrought.

Maliciousness, being an intangible state of mind, is extremely hard to prove in a court of law. It is therefore extremely rare for courts to rule in favor of public figures suing for defamation. The idea is that the notable and powerful already have wide-reaching platforms at their disposal to dispute unflattering or potentially false claims. The president has a press secretary precisely for this reason; and, perhaps more effectively, one of the world’s most widely-read Twitter accounts. Consequently, libel suits by public figures are typically recognized for what they are—weapons of intimidation, often deployed by the powerful against a free press. This is no exception.

“It’s a shot across the bow,” Stanley Pottinger, a former Justice Department attorney under the Nixon, Ford, and Carter administrations, said on MSNBC today (Jan. 4). The cease-and-desist letter was likely intended to put Henry Holt on notice, and encourage lawyers and editors to reevaluate some of the book’s more salacious details prior to its scheduled release. The likelihood that it precipitates an actual lawsuit is slim, not least of which because Trump habitually threatens lawsuits and rarely follows through.

If Trump were to actually file a suit against Henry Holt, requesting a halt to the publication and/or distribution of Fire and Fury, a court could find the suit to be an instance of “prior restraint”—that is, government censorship of speech prior to its actual expression or publication. A prime historical example of prior restraint is on display in Steven Spielberg’s The Post, which documents the Nixon administration’s attempts to enjoin The New York Times and Washington Post from publishing excerpts of classified Defense Department reports on the Vietnam War. The United States Supreme Court eventually struck down those injunctions, holding that the government must show evidence that publication of disputed information would cause “grave and irreparable” danger. It doesn’t seem likely that a book trading on West Wing gossip, name-calling, and internal rivalries would qualify.

In any event, such a lawsuit could definitely backfire against Trump—because it would open the White House up to discovery by Henry Holt’s legal team. Discovery is a pre-trial procedure in which a party’s lawyers have the opportunity to collect evidence from opposing counsel. Trump’s aides would deposed by Henry Holt’s lawyers. If Wolff maintained tape recordings of his interviews with sources, those would likely be entered into the record as well. With special prosecutor Robert Mueller reportedly closing in on the Trump campaign’s alleged Russian connections, the last thing this White House wants is another outsider lawyer snooping around the West Wing.

Were Trump to pursue a lawsuit against Bannon, things could get very interesting.

Trump’s cease-and-desist letter describes Bannon’s statements as “defamation by libel and slander,” and also alleges breach of confidentiality and non-disparagement agreements reportedly signed upon his exit from the White House. Legally, if a statement is true, it can’t be defamatory. So while Bannon’s statements might legitimately violate his NDA with the White House, it is impossible to violate a confidentiality agreement with false statements. Should Trump pursue legal action against Bannon on grounds of breached confidentiality—and Harder writes that “legal action is imminent”—it would be an implicit admission to the veracity of at least some of Bannon’s claims.

Bannon’s NDA could also wind up influencing the presidential primaries in 2020. Many speculate that Bannon believes Trump failed on delivering on the populist-nationalist message that puthim in the White House, and that Bannon intends to take up the the mantle of #MAGA leadership with a 2020 presidential run. If that means a Republican primary face-off between Trump and Bannon, the NDA could play a big role. How would Bannon run against Trump without the ability to disparage him?

These letters pose a lot of interesting questions. But at the end of the day, they’re typical of Trump’s legal MO. Frivolity, self-contradiction, and intimidation tactics have always been the name of the game. And potential self-incrimination almost always rears its head.