Of all the grim prospects of a Trump presidency, the thought of a reality TV star at the helm of America's nuclear arsenal should top the list. And not just any reality TV star. To wit, I could plausibly see Mike Rowe from Dirty Jobs, Bear Grylls from Man vs. Wild, or Bob Vila from This Old House realistically assume the mantle of commander in chief. Even one of those nice interior design ladies from HGTV would have a better temperament to control a nuclear arsenal than Donald Trump, and the Oval Office would look fantastic to boot.

It shouldn't be a laughing matter. Trump's long, ugly campaign has swelled with absurdities, bluster, obscene chest thumping, and baffling claims that leave allies afraid and adversaries eager. He's spoken of deliberately killing the families of terrorists, and using torture to extract information from captured terrorists. He thought that South Korea and Japan should leave the U.S. nuclear umbrella and perhaps develop nuclear weapons on their own.

This of course would undo half a century of non-proliferation policy. This is where the United States offered the protective aegis of its nuclear umbrella to its allies, so that they would not develop weapons of their own. To the point, South Korea and Japan could build a nuclear weapon practically overnight, should they choose. The point, which is lost on Trump, is that such a move would be spectacularly dangerous for Far East security.

Most concerning was an allegation from MSNBC host Joe Scarborough, who said that a foreign policy expert was asked three times by Donald Trump why we couldn't use nuclear weapons. The takeaway line from the Apprentice star and occasional WWE guest was "if we have them, why can't we use them?"

It's an unattributed quote that the Trump campaign denies, so a grain of salt is necessary. But at the risk of hyperbole, this is concentrated and weaponized insanity.

U.S. nuclear forces are a shadow of their Cold War strength, but it is still the most capable and potent arsenal in history. And if it's ever deployed, it will reshape the environment and the geopolitical order.

The force is remarkably stable and secure, though it is aging. For decades, the United States kept tens of thousands of warheads on alert or in reserve. These weapons were constantly on the move, in trains, in the sky, on and under the seas. But not a single one went off on accident, and not a single one was lost to theft.

It's a testament to the skill of the amazing young men and women who man the walls of the nuclear deterrent. But it also serves as ready proof that, for decades, the commander in chief has favored sound and responsible nuclear policy.

The entire nuclear chain of command rests on the responsibility and sensibility of the president.

I had the honor of pulling 300 nuclear alerts in a Minuteman III, REACT-A control center. An alert is a 24-hour shift 100 feet underground, with 10 thermonuclear missiles on the other end of your weapons console.

I served during the Bush 43 and Obama administrations, and in both terms I knew that I would only be asked to do my duty as a last resort. If I received "the order," encoded through multiple thick encryption protocols, I knew it meant that the United States was under attack. With Donald Trump at the helm, no such assurances can be made. And none can be given.

The American people must consider fitness and mental stability of entrusting the levers of our strategic forces to a vicious demagogue. Donald Trump is unfit for the White House and unfit to serve as commander in chief. He is undeserving of the responsibility to lead the young men and women who do their duty daily.

Those nuclear professionals have no expectation of praise or medals as they carry out a tough assignment. But they do rightly expect, and deserve, a leader who acts worthy of their grave responsibility.

John Noonan, a former Air Force officer, was national security advisor to Governors Jeb Bush and Mitt Romney.