More Than 700 Current and Former National Security Officials Back Harris

More than 700 current and former national security leaders, as well as former military officials, endorsed Vice President Kamala Harris in a letter released on Sunday, arguing that only she had the temperament and values needed to serve as commander in chief.

The signatories of the letter, which was organized by the group National Security Leaders for America, included former secretaries of state and secretaries of defense, former ambassadors and retired generals. They argued that former President Donald J. Trump posed a threat to both national security and the United States’ democratic system.

Among the most prominent names were the former defense secretaries Chuck Hagel, a Republican who served under President Barack Obama; William Cohen, a Republican who served under President Bill Clinton; and William J. Perry, a Democrat who served under Mr. Clinton.

The former secretaries of state Hillary Clinton and John Kerry, and the former defense secretary Leon Panetta, also signed the letter, though their support for Ms. Harris was already clear.

The retired military leaders who signed included Rear Adm. Michael E. Smith, the president of the organization that released the letter, and Gen. Michael V. Hayden, who led the C.I.A. under President George W. Bush.

“This election is a choice between serious leadership and vengeful impulsiveness,” the letter said. “It is a choice between democracy and authoritarianism. Vice President Harris defends America’s democratic ideals, while former President Donald Trump endangers them.”

It continued: “We do not make such an assessment lightly. We are trained to make sober, rational decisions,” and added: “We know effective leadership requires in-depth knowledge, careful deliberation, understanding