Former U.S. national security adviser Susan Rice delivered a damning critique Thursday of Donald Trump and his foreign policy agenda for aiming to appease Russian President Vladimir Putin during the ongoing invasion of Ukraine.

“The fundamentals of national security — that America needs to be strong, that we need to stand with our allies, we need to stand for our values, we have to mean what we say … never used to be under serious question,” she told MSNBC’s Lawrence O’Donnell.

“And along comes Donald Trump, who really is like the Neville Chamberlain of the Republican Party,” Rice continued. “He’s an appeaser. He’s a surrender monkey. And that’s what we’re seeing in his approach to Ukraine.”

Chamberlain exercised a policy of “appeasement” during his tenure as British prime minister in the years leading up to World War II, in a failed attempt to prevent Nazi dictator Adolf Hitler from expanding German control of Europe and waging war on the United Kingdom.

The document was signed by current and former defense officials, including former defense secretaries Chuck Hagel and William Cohen — Republicans who served respectively under Democratic former Presidents Barack Obama and Bill Clinton — as well as ex-CIA director Michael Hayden.

Charles Rex Arbogast/Associated Press

Trump spokesperson Steven Cheung told The New York Times that these were “the same people who got our country into endless foreign wars and profited off of them while the American people suffered,”

Rice maintained that national security could be a bipartisan middle ground.

“Until recently, foreign policy and national security were played between the 40-yard lines between Democrats and Republicans,” she told O’Donnell. “There was a center that was a responsible, rational center.”

Rice concluded by emphasizing Harris “has the temperament and the intellect and the vision and the experience to be on day one an effective and strong commander-in-chief.”