Every American in the armed forces, and any veteran who has served, hopes and prays for peace and stability under the recently reelected, incoming commander in chief. Political leanings are no factor here. We salute and serve because that’s who we are — even as our oaths may soon be tested as the next frontline in the war for America’s soul.

Everyone in the military takes an oath to “support and defend the Constitution of the United States against all enemies, foreign and domestic.” Enlisted service members also swear to “obey the orders of the President of the United States and the orders of the officers appointed over me, according to regulations and the Uniform Code of Military Justice.” Given Donald Trump’s threats to use the military against his own enemies, some wonder with dread: What will the military do if the president gives unconstitutional orders? While nobody would ever want such a challenge, I am fully confident that Americans in uniform will honor the highest duty we swore, which is to the Constitution.

My introduction to the oath came at West Point, when a Vietnam War veteran and professor put it to me straight: “Just who do you want to be? An employee? Or a professional, self-abnegating servant of the nation?” It was an admonition and expectation that, decades on, may be the most consistent North Star I’ve known. I fought with better men than me who died in Iraq, I spent years and years overseas missing birthdays and everydays with my young daughters, and my final act in uniform was to give away a kidney at Walter Reed National Military Medical Center. I wouldn’t have done those things if I hadn’t meant the words spoken at my commissioning ceremony, pledging my “true faith and allegiance,” which means more to me than my next breath even now that I’ve retired from active service.

I’m not alone. Millions of others put that same oath at the center of their lives. I liken it to a baptism; instead of joining a faith community, we pledge our lives to the ideals of the United States.

These aren’t just words. They’re practical; they’re our common ground regardless of where we’re from or what political differences we might have. They build trust for cohesion to function amid terrifying and violent circumstances. And these oaths that power American national security will likely be tested in coming years.

During his first administration, Trump threatened use of the Insurrection Act (of 1807). At one point he suggested the military should shoot protesters in the legs, which clearly would have been illegal. More recently, he’s said he would invoke the Alien Enemies Act (of 1798) and may use the military to detain and deport noncitizens. If either order came to pass — for the 1st Armored Division to roll into Cincinnati or the 82nd Airborne to drop on D.C. — it would immediately pose a can’t-fail test for the American military.

What will the troops do? Must members of the U.S. military blindly obey their commander in chief? Or should these individuals always defy orders they consider unconstitutional?

Unfortunately, the answers aren’t straightforward.

The U.S. military oaths counsel thoughtful loyalty, not unthinking fealty — and the law treats each troop as responsible for making the right choice. There’s no respondeat superior (“let the master answer”), no “just following orders” defense, a principle discredited since World War II when the international community held middlemen and foot soldiers responsible for their war crimes that were ordered by Nazi commanders. Thus the military’s first duty is to obey legal orders (and disobey illegal orders). Our generals and JAGs (military lawyers) must lead the institution through the ethical minefields ahead. They, and everyone in camo, must stand their moral ground with courage indistinguishable from the battlefield. Because their oaths expect they “should be prepared not only to die for [their] country, but to be fired for it,” in the words of John Silber.

There’s another bedrock obligation for military members, a principle that has made the uniformed services among the last remaining trusted institutions in the nation. To preserve American democracy as it exists, the armed forces must always remain politically neutral and not side with any politician or party. This is where things get even messier.

If a president ordered the military to shoot protesters, or to become substantially involved with wholesale domestic detentions, what the military must do — obey or defy — depends heavily on the situation’s specifics and any actual violent threat. To issue an advisory opinion without that context would be malpractice. The world is as gray and complex as our oaths are pure and simple.

Because there could be constitutional circumstances for military engagement on U.S. soil. We just can’t know yet whether controversial orders will come, and if so what the situation will be.

What we can know is that the U.S. military is a house with good bones. It’s an institution that’s prepared for dire circumstances like these for quite some time. A century ago, a chaplain at West Point penned the “Cadet Prayer,” which advises: “Make us to choose the harder right instead of the easier wrong.”

Let’s hope that our next president does not attempt to abuse his authority as commander in chief. But if he does, Americans in uniform will choose the harder right — so help us God.

ML Cavanaugh recently retired after 25 years in the U.S. Army. He co-founded the Modern War Institute at West Point. @MLCavanaugh