If you worry that President Trump's temperament and character are inappropriate for the commander of the U.S. nuclear forces, you may be tempted to place your hope in Defense Secretary James Mattis. In fact, allaying those concerns seems to be one reason Trump selected Mattis. Calm, thoughtful, and practical, Mattis brings everything to the table that Trump seems to have abandoned.
It is true that Mattis has a role in the process that would begin with President Trump's order to launch and end 4 minutes later with nuclear missiles firing from their silos. The order to use nuclear weapons is subject to the so-called "two-person rule," a control mechanism meant to reduce the possibility of unauthorized or unintended launch. The Secretary of Defense is the "second man" to the president in the launch process; once the order is given, he must authenticate the command before it is transmitted down the line.
Here is the first caveat: This control mechanism is not a veto. It is not intended to guarantee that the president is sane, that his analysis is sound, or that a nuclear launch is critical to U.S. security.
If Trump authorized a nuclear strike, Secretary Mattis is not meant to act as a voice of reason. His responsibility is simply to confirm the order, not the soundness of the decision. Imagine the horror of that position: asked not to evaluate but only to authenticate nuclear war, complicit in the machinery of absolute destruction but without agency to disrupt or divert it.
It is possible that Mattis would refuse to authenticate Trump's command. His position demands absolute obedience. Such an act of defiance would require enormous courage and conviction, perhaps more than is fair to expect from any human being. Yet hypothetically, at least, refusal is possible.
Unfortunately, we then encounter the second problem.
Even heroic disobedience from Mattis would not be enough to stop Trump's nuclear war. The current U.S. president -- famous for the delight with which he declares "you're fired!" -- has already shown us how easy it is to remove dissenters. Attorney General Sally Yates' refusal to legally defend Trump's immigration ban was quickly followed by a pink slip.
The swift removal of Sally Yates is a warning to those who seek comfort from the sound judgment of Defense Secretary Mattis. If Mattis refuses to authenticate the president's order for a nuclear strike, Trump can simply dismiss him. Authentication responsibilities would then move down the line of the Department of Defense succession.
The two-person rule is not an effective control mechanism when one of those people is the most powerful individual on earth and the other is their subordinate, subject to instant replacement.
By design, Donald Trump's command of our nuclear arsenal is unassailable. It isn't enough to hope that the system breaks down -- the system itself has to change.
Luckily, change is still possible. Two members of Congress have introduced legislation to partially correct this problem. The proposed bill would prevent the the first use of nuclear weapons unless Congress declares war, introducing a democratic check to the president's ability to launch nuclear weapons. Such a law would strip autocratic authority over the U.S. nuclear arsenal from Trump, who cannot replace members of Congress with more willing sycophants.
That any one person commands such absolute power is a terrible threat, both to our communities and to our democracy. President Trump is not the cause of the problem, but he brings into laser focus the urgent need for a solution.