President Donald Trump isn’t making America great; he’s ignoring American values, according to a retired admiral who supervised the raid that led to the death of Osama bin Laden.

William McRaven, former commander of U.S. Special Operations, warned in a chilling New York Times opinion article Thursday that America is under attack from inside the Oval Office.

McRaven recounted attending recent events honoring members of the military and the intelligence and Special Operations community. He was struck by participants’ steadfast belief in American values “worth sacrificing everything for.”

But “beneath the outward sense of hope and duty, there was an underlying current of frustration, humiliation, anger and fear,” he wrote. “The America that they believed in was under attack, not from without, but from within.”

He lamented the “assaults on our institutions: on the intelligence and law enforcement community, the State Department and the press.” Those loyal to the nation have “seen our leaders stand beside despots and strongmen ... they have seen us abandon our allies.” He quoted a retired four-star general as telling him: “I don’t like the Democrats, but Trump is destroying the Republic!”

McRaven asked: “If we are not the champions of the good and the right, then who will follow us? And if no one follows us — where will the world end up?”

Trump “seems to believe that these qualities are unimportant or show weakness. He is wrong,” McRaven wrote.

“If this president doesn’t understand their importance, if this president doesn’t demonstrate the leadership that America needs, both domestically and abroad, then it is time for a new person in the Oval Office — Republican, Democrat or independent — the sooner, the better. The fate of our Republic depends upon it.”

Read McRaven’s entire New York Times op-ed here.