The president’s detractors are simultaneously applauding McRaven’s statement and lamenting that it will have no impact. They are correct that McRaven’s op-ed is unlikely to change any minds among the president’s base. It will not embolden congressional Republicans to finally take a stand. Certainly it will not shame Trump into ceasing his relentless campaign against any and all who would dare oppose him. But the letter isn’t designed to do any of those things.

McRaven’s intended audience is not the general public, nor the president to whom this letter is addressed. Rather, McRaven is speaking to a small community of his peers, those who have served in high-ranking national-security posts, both in and out of uniform, and have, like McRaven, remained staunchly apolitical. McRaven’s entire letter was just 250 words, but his message to that group required fewer than 20: The retired admiral would feel privileged to lose his security clearance, he writes, so “I can add my name to the list of men and women who have spoken up against your presidency.”

McRaven—a man so assiduously apolitical that he strenuously slapped down nascent rumors that he was being considered as a potential vice-presidential candidate—has now added his name to those who publicly oppose this president. In doing so, he is saying that the time has come for others in his circle to do the same.

Indeed, the following morning, 12 former intelligence-agency directors and deputy directors signed a public letter admonishing the president and urging that security-clearance decisions remain apolitical. Former CIA Director and Secretary of Defense Robert Gates joined a day later. At least five of the signatories—including Gates, David Petraeus, and George Tenet—had not previously publicly criticized this administration.

This was followed by an additional open letter sent Friday evening and signed by 60 former CIA officials, who expressed a shared “belief that the country will be weakened if there is a political litmus test applied before seasoned experts are allowed to share their views.”

Until now, a great many other members of this small community have remained silent. They recognize that as the president assails the norms of apolitical national security, there is a risk that responding in kind only hastens institutional destruction. After all, what better way to prove the existence of a “deep state” working against the president than unified opposition of national-security officials rising from the depths?

It is against this backdrop that McRaven penned his missive. In speaking out, McRaven tells his peers that the cost of silence now outweighs the benefits of remaining above the fray.

During the campaign, retired General Martin Dempsey, the former chairman of the Joint Chiefs of Staff, wrote his own Washington Post open letter on retired military officers appearing at the Democratic and Republican conventions, writing that former officers “have an obligation to uphold our apolitical traditions. They have just made the task of their successors — who continue to serve in uniform and are accountable for our security — more complicated. It was a mistake for them to participate as they did. It was a mistake for our presidential candidates to ask them to do so.” Dueling letters signed by retired generals and flag officers in support of Hillary Clinton and Trump likewise drew rebuke from scholars of civilian-military relations.