Daniel Akerson was chairman and chief executive of General Motors from 2010 to 2014 and was vice chairman and special adviser to the board of directors for the Carlyle Group from 2014 to 2016.

I am the son of a World War II and Korean War veteran. As a young man, the men I respected most were my father and my uncles, who collectively fought in the Battle of the Atlantic and the invasions of North Africa, Sicily, D-Day, Iwo Jima and Inchon. I came of age in the service of our nation. I never had a draft card. I entered the U.S. Naval Academy before my 18th birthday and served in the Navy for five years. My older brother volunteered as well. Simply put, it was expected. We were raised in a good Catholic home and believed in God and country. My wife of 44 years and I have sought to pass these values to our kids and grandkids.

And I have always voted for Republicans for president. Not this year.

The compelling rationale behind this decision: leadership. A good leader must demonstrate such qualities as competence, integrity, empathy, character and temperament. Hillary Clinton has these essential qualities. Donald Trump does not.

Trump simply lacks the competence to serve as president of the United States. His knowledge of economic policy and foreign affairs is rudimentary, at best; his views are misguided. His threat to impose prohibitive tariffs on trade would repeat mistakes that contributed to the Great Depression. His words and actions have rattled our European and Asian allies at a time when Russia and China are resurgent. He has demonstrated neither the capacity nor the inclination to learn from experts in global economics.

Trump claims great business prowess. Running the U.S. government is perhaps the most complex global chief executive job in the world. Everything one does as the leader of the free world is watched by markets, foreign governments, our competitors and our enemies. This requires a steady hand and temperament.

When I worked at General Motors, our global operations comprised more than 100 plants and roughly a quarter-million employees. Supply-chain management and the orchestration of commodities, parts and components around the globe required a multinational, interdisciplinary effort. In every chief executive job I have had, my team and I spent countless hours analyzing global trends, listening to experts, learning from others and making informed, reasoned decisions. Trump does none of that. While running a successful hotel business is honorable and hard work, there is no comparison to running a sophisticated global operation such as the U.S. government. Trump is simply not up to a job of this complexity.

During a speech in Youngstown, Ohio, Republican presidential nominee Donald Trump outlined some of his plans to defeat the Islamic State and protect the United States. (Sarah Parnass/The Washington Post)

Long ago, I learned an old Navy saying from a good friend and now-retired admiral: “Ship, shipmate, self.” This motto set the priorities for my life during my service. The civilian equivalent would be “country, fellow citizen, self.” As individuals and as a nation, we must aspire to serve the greater good. We must exhibit the empathy that places the greater good of the nation and its people above individual self-interest.

Unfortunately, Trump has appealed to the lowest common denominators in our society: prejudice, xenophobia and intolerance. He has mocked people with disabilities, tarred ethnic minorities, demeaned women and insulted religious leaders, including the pope.

When Trump questioned the patriotism and sacrifice of Sen. John McCain (R-Ariz.) and, thereby, other prisoners of war, he demonstrated a complete lack of respect for the men and women in uniform, as well as our veterans. He appeared unable to empathize or comprehend the sense of isolation and despair associated with years of imprisonment. But he did not stop there.

When asked how he has sacrificed for our country, Trump compared his experiences in real estate to that of a mother who lost her son after that brave young man volunteered for service in the U.S. Army. Trump’s complete lack of empathy and his failure to understand the heartache of a grieving mother disqualify him from being commander in chief. What kind of person equates the sacrifice of the loss of a child to that of creating jobs or making money?

Trump has resorted to schoolyard name-calling and skewed the truth too many times. I simply do not believe that Trump could stand tall like John F. Kennedy did during the Cuban Missile Crisis, demonstrate the strength of Ronald Reagan in bringing about the end of the Cold War or articulate the vision of George H.W. Bush to support a unified Germany when the wall came down.

By contrast, Clinton has been tested. She has demonstrated balance, calm and an even temperament. She has an unparalleled knowledge of foreign and economic policy; she has run complex organizations such as the State Department. Over the years, she has demonstrated that she can take criticism and work with even her most strident political opponents. Like other leaders, including myself, she has made mistakes. I believe she has learned from those mistakes. In my opinion, she is ready to be commander in chief on Day One.

Many of my fellow chief executives will question my decision to speak out. My choice is grounded in the Midwest values that I learned from my parents and grandparents. I hope and believe that one day my grandchildren will be proud that I stood up to speak out about what is right for our country. Ultimately, our greatest duty to our country is to put our future, and our children’s future, above partisan politics.