Thanks to a leak to the press, we all now know that John Bolton has written an explosive account of President Trump’s fateful decision to withhold hundreds of millions of dollars in security assistance from Ukraine. But it is far from clear how much of this story the public will be permitted to read, and when.

Like millions of others who once held a security clearance, Mr. Bolton, President Trump’s former national security adviser, is barred from publishing a book or blog post about his experience in government without first submitting it to official censors. As a result, what the public will see of Mr. Bolton’s account of malfeasance and corruption in the White House is, to a disturbing extent, up to the White House itself to decide.

The logic behind the requirement of prepublication review is easy to understand. Public servants with security clearances have access to classified information. The review system allows agencies like the Central Intelligence Agency and Defense Department to ensure that former employees who write books and other public materials don’t disclose secrets inadvertently. (Those who actually intend to disclose classified information don’t submit their manuscripts for government review, of course — and they can be prosecuted for revealing secrets.)

The system amounts to a prior restraint on speech, because it gives the agencies the chance to censor manuscripts before their publication. Though prior restraints are usually unconstitutional, including in the national security context, the government argues that they are justified because they are imposed through nondisclosure agreements signed by employees.