Opinion: I was a Navy admiral. Voting for Trump threatens US stability.

I am one of hundreds of former national security leaders who have endorsed Vice President Kamala Harris for president. We recognize Vice President Harris’ superior qualifications for the job and have been concerned for some time about the truly troubling prospect of the return of Donald Trump as commander in chief.
This swell of support for Harris should come as no surprise. She has proved her ability to address the most difficult national security challenges, from rallying allies against Russia’s invasion of Ukraine to confronting China’s provocations in the Indo-Pacific and advancing U.S. leadership on space and artificial intelligence.
She is a steadfast supporter of service members, veterans, their families, caregivers and survivors. She has met with our service members all around the world, from NATO’s eastern flank to the Korean Demilitarized Zone. She has spoken repeatedly about the extraordinary skill, discipline and dedication of our armed services. And she will make sure the United States honors its sacred commitment to those who defend our freedoms and our way of life, including protecting the benefits they earned from their service.
Trump has lost the trust and respect of veterans by verbally attacking Gold Star families. He suggested firing senior military leaders and replacing them with football coaches. As confirmed by retired Marine Corps Gen. John Kelly, a former White House chief of staff, Trump referred to Americans who died in war as “suckers.”
Recently, he even alleged that the Presidential Medal of Freedom is superior to the Medal of Honor.
But the former president’s policies and actions are more damaging than his words. He mishandled the COVID-19 pandemic, which had a devastating impact on military families as well as the American population at large. He routinely uses the military as a political prop, including at Lafayette Square outside the White House.
In recent weeks, Trump even desecrated the memory of our fallen heroes at Arlington National Cemetery by turning a memorial service for deceased service personnel into a political event.    
Opinion:Trump’s appalling desecration of Arlington National Cemetery shows he still can’t be trusted
Most profoundly concerning is the prospect of what Trump would do in a second term, untethered from needing to follow the Constitution.
Earlier this year, I joined 18 other former Defense officials to file a brief with the Supreme Court. We argued that a president free to order the armed forces to carry out unlawful orders without any legal consequence for themselves would threaten to destroy the trust that must exist for the civilian-military relationship to work in our country.    
What are the chances this could happen? One need only remember Jan. 6t, 2021, when a mob of Trump loyalists urged on by the then-president stormed the Capitol and attempted to prevent the transfer of power.
Trump’s big lie and attempt to subvert democracy shocked and angered members of the military community who have dedicated our lives toprotecting democracy. 
The world is more volatile and dangerous now than at any time in my memory.
The American people need a principled leader who is competent to navigate and lead us through competition and crisis. For the sake of our nation’s safety and stability, I urge my fellow veterans not to vote for Donald Trump. He is unfit to return to the presidency and poses a significant risk to the American people and our democracy.
He is not a disaster waiting to happen. He is a disaster that has already happened.
Adm. Steve Abbot spent 34 years in the U.S. Navy, retiring as deputy commander in chief of U.S. European Command. He also served as deputy Homeland Security Adviser to President George W. Bush and as president of the Navy-Marine Corps Relief Society.