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Congress has unintentionally shifted the burden of preventing an unconstitutional war squarely onto the military. By failing to exercise its war powers, it has positioned the American military as a firewall made of parchment between itself and the White House. Democratic members of Congress and the Senate have issued solemn warnings regarding unlawful orders and disobedience, hoping the military will do what Congress hasn’t: prevent an unconstitutional war.
This is not the right path. Making the military the last barrier to unconstitutional war corrodes civilian control, encourages executive overreach, and risks politicizing obedience itself. It is also of questionable efficacy, serving as a Hail Mary pass given the military’s robust institutional obedience to its commander in chief. While Democrats speaking out about illegal orders and resistance from the ranks are on sound legal ground and are expressing understandable frustration, Congress should do its job instead of looking to the military to counter such threats.
Orders to carry out a large-scale military operation against Greenland — that is, engage in war, similar to U.S. invasions of Iraq in 1991 and 2003 — without Congressional approval would fundamentally violate the Constitution. The country’s framers wanted Congress to decide when the people’s blood and treasure would be spilled. Such Greenland orders would also violate international law and destroy NATO clear statutory protection of the latter.
While a Greenland invasion now seems unlikely, Iran is now the frame through which we view this issue: Last weekend, Trump launched another war against Iran, without formal Congressional approval of any sort. This seems like a more complicated legal case since Iran is clearly an adversary and Denmark, which owns Greenland, is an ally: However, this war on Iran is still unconstitutional, given that Congress has played zero role in launching it.
The Constitution, through its declaration of war and funding powers, gives Congress a preeminent stake in making the perilous and momentous decision to engage in an extensive military campaign against Iran. Exercising such power requires congressional action, not passivity in the face of a commander in chief’s desire to launch an offensive war — even a war against a repressive regime that has recently massacred thousands of its own citizens. Wars against murderous autocracies are still wars, paid for by U.S. taxpayers and U.S. servicemembers’ lives. The president’s constitutional authority is to smartly execute any and all wars authorized by the people’s representatives in Congress: It is not to usurp that very power.
How did we arrive here? What are the actual options for military officers facing illegal orders?
Answering those questions requires confronting two parallel realities. The first is institutional: Congress has, over time, tolerated an increasingly elastic understanding of presidential war-making authority. Through expansive authorizations, ambiguous statutory language, and habitual acquiescence after the fact, legislators have allowed the center of gravity to drift toward the executive branch. That drift has reshaped expectations across government, including within the armed forces.
The second reality is legal and cultural: The military is structured around obedience. Its professional ethic prizes disciplined execution of civilian direction, reinforced by a legal regime that presumes orders are lawful and punishes deviation. The space in which a servicemember may safely refuse an order is narrow, and the consequences of misjudgment are severe. Against that backdrop, exhortations from elected officials that the ranks should stand as a constitutional backstop take on a different cast. The only people in uniform who have some space for resistance against illegal orders can be found at the top.
Corrosion of Civilian Control and Executive Overreach
By making the military the primary obstacle to unconstitutional war, Congress degrades civilian control and encourages executive branch overreach. Civilian control of the military, constitutionally balanced between the White House and Congress, is designed to ensure military subservience to democratic will and the rule of law. Critically, Congress’s powers to declare and fund war are part of civilian control, and use of such powers importantly checks the commander in chief.
Congressional war powers, except in the case of sudden attack, classically meant that the military goes to war not simply when the president demands, but only when Congress approves. However, decades of unchecked executive branch military adventurism have fundamentally altered this design. This power shift is over a century old, as demonstrated by President William McKinley’s troop deployment to China in 1900 to fight in the Boxer Rebellion without congressional approval. When Congress has tried to put the brakes on unilateral war by the president, it has done so only half-heartedly — the failure of the Vietnam-era War Powers Resolution is well documented. Even when Congress has explicitly approved war, such as by its broad 2001 Authorization for Use of Military Force, it has failed to enact appropriate limits — leaving this huge grant of authority on the books 25 years later, despite repeal attempts.
Congress’s anemic attempts last year to curb executive military action against Venezuela (and similar recent efforts to block a war against Greenland) reveal that congressional war powers, and hence civilian control, have greatly shifted to the White House. Correspondingly, Congress’s repeated failure to reform the dangerously vague Insurrection Act — reform needed to prevent the White House from abusively pitting the military against “We the People” domestically — similarly shifts civilian control to the executive.
Such failures rest civilian control of the military less “in the hands of the representatives of the people” as the founders intended, and more in the hands of an increasingly authoritarian executive — thus amplifying the risk that the military could be turned against democracy.
As for executive overreach, it’s noteworthy that the military didn’t resist orders to carry out January’s congressionally-unauthorized invasion of Venezuela that captured President Nicolás Maduro — despite the Trump administration’s admission that the operation constituted war. However, the Department of Justice insisted that it was not “war in a constitutional sense,” and therefore didn’t require congressional preapproval. This twisted legal rationale has been repeatedly used by prior administrations — yet Congress hasn’t challenged it to successfully claw back its power. It has instead acquiesced time and time again by continuing to fund military operations under similar executive branch reasoning.
Given this Article II (commander in chief) inclination to accumulate Article I war powers — particularly the congressional power to authorize war derived from the declare war clause — through wordsmithing and congressional inaction, Trump’s lawyers could similarly categorize a military invasion of Greenland (or Iran) as a war that does not require Congress’s go-ahead. Such legal rationale would produce superficially lawful military orders, despite no congressional approval — orders the military would be hard pressed to disobey, despite their violation of the Constitution.
Politicizing Obedience: The Reality of the Law of Military Orders
Hoping that the military will simply disobey unconstitutional orders to invade other countries risks politicizing military obedience itself, plus it ignores the complexity of how military orders work. Instead of expecting military resistance to unconstitutional war, Congress should be doing everything it can to prevent the military from having to grapple with such orders in the first place.
The Law of Military Orders
The law of military orders makes military resistance in this arena both challenging and unlikely. Disobedience is fraught because military law and command structure greatly disincentivize refusal of orders. Insubordination is an extraordinary exception to military standard operating procedure, punished as anathema to good order and discipline. Hence obedience is the military default and in its DNA.
It is well established that while obedience is a vital part of military culture, servicemembers’ duty to obey, upon pain of court-martial, only runs to lawful orders. Unlawful ones should be refused. However, all orders issued by proper authority that relate to a military duty are presumed lawful. Those choosing to disobey orders that they believe are unlawful therefore do so at their peril. Military judges ultimately decide whether an order is lawful during a court-martial for disobedience — a risk few servicemembers understandably want to take.
Furthermore, the only circumstance in which orders must be disobeyed is if the recipient either knows the order is unlawful, or “a [person] of ordinary sense and understanding” would know it was unlawful. In practice, this narrow duty to disobey exclusively runs to “patently” unlawful orders — meaning those ordering crimes such as a command to kill a sleeping detainee, murder helpless civilian villagers in My Lai, Vietnam, or shoot a peaceful protester in Chicago. If the patently unlawful order is obeyed, the servicemember is guilty of the crime committed, with “superior orders” failing as a defense.
This “duty to disobey unlawful orders” category is therefore quite small both in law and effect, with consequences regarding orders to fight an unconstitutional war. If an order is unlawful but does not order an actual crime — such as a hypothetical Greenland invasion order without congressional approval – there is no downside for obeying it, as there is no criminal or other liability for doing so. While unlawful because such an order would impermissibly arrogate war powers to the president, orders to invade Greenland or Iran are not orders to commit crimes. They are therefore not patently unlawful per military law and trigger no legal duty to disobey.
Attack and invasion orders are not crimes because the overall illegality of a war does not make unlawful otherwise lawful acts of war. The distinct legal paradigm that governs the actual conduct of war is generally considered separate from the legality of the war itself. Therefore, a lethal U.S. F-16 strike on Danish soldiers in Greenland (or on Iranian military barracks in Iran) during an unconstitutional (and internationally unlawful) U.S. military campaign against either would not be murder. Such strikes would instead constitute the lawful killing of enemy troops per the law of war, regardless of the overall illegality or unconstitutionality of the war.
Inhospitable Judicial Reception to Disobedience
In sum, unconstitutional orders to engage in major military operations against Greenland or Iran (or elsewhere) are not the type of illegal orders — to commit crimes — that trigger a duty to disobey for those in uniform. This makes disobedience of such unlawful orders a risky proposition for servicemembers, with obedience far easier. They can disobey such orders based on a belief of their illegality, and it would go to the courts to decide — but servicemembers have not fared well when court-martialed for resisting unconstitutional wars.
Military courts have historically been reluctant to entertain disobedience defenses based on the claimed illegality of the conflict. They have seemingly conflated non-justiciability issues with legality of the order itself, to the detriment of servicemembers. Furthermore, the few federal courts to touch this issue have also not been encouraging, and likely will continue to refuse to adjudicate war-initiation disputes. In 2016, a District of Columbia federal court negatively responded to an Army captain’s challenge that the anti-Islamic State military campaign was not properly authorized by Congress. The court concluded that “it appears well-settled …. that there is no right, let alone a duty, to disobey military orders simply because one questions the Congressional authorization of the broader military effort.”
Perhaps both military and civilian courts would be more willing to tackle war powers issues in an extreme case, such as a Greenland invasion. But they may continue to punt, posing a substantial risk to servicemembers who want to disobey, while letting down congressmen who hope for disobedience. And given such orders’ lack of patent illegality, claims from one political party that war-making orders are unlawful risks turning both disobedience and obedience into political acts, versus the duty of those in uniform.
Do Senior Military Leaders Have a Responsibility to Resist?
If push comes to shove and the military remains the only obstacle to unconstitutional war, it falls upon senior officers, and not upon the military as whole, to resist unconstitutional — or otherwise unlawful but not criminal — orders. While we didn’t see that happening in the initial strikes against Iran this past weekend, if Trump ordered U.S. ground forces to take Tehran without Congressional approval or, for a different example, unilaterally ordered troops into Mexico to help that nation regain control from its armed drug cartels — hopefully senior military leaders would pause. They should pause before executing such unlawful orders because responsible command demands that the most high-ranking commanders not transmit illegality to their subordinates. Americans should not expect the rank and file to refuse operational orders from their chain of command, orders that are by necessity sanitized of constitutional war powers issues, but they can and should expect more from those at the top.
Senior officers are better positioned to effectively push back given their proximity to senior civilian decision-makers. They possess greater understanding of the constitutionality of orders to go to war and flag officers face less personal risk in resisting potential orders. They can protest early on — since wars require preparation, providing time for challenge — and then choose to retire before receiving an unlawful order. Adm. Alvin Holsey comes to mind, with his fall 2025 retirement reportedly linked to his concerns regarding the unlawful military boat strike campaign in the Caribbean. While such courage seems to be in short supply, it may be what is needed if the military is to remain truly subservient to the will of the people — at least given congressional inaction.
Finally, the idea that greater responsibility falls on senior military leaders for refusing to execute illegal wars is not novel, and has roots in Nuremberg. If the United States was a party to the International Criminal Court or had otherwise codified the crime of aggression, senior U.S. military officers, alongside civilian leaders, would be criminally liable for waging internationally unlawful wars. Troops beneath them would bear no criminal accountability for the war itself. And that’s how it should be, as senior military leaders have the capacity of either enabling illegality directed by the White House, or of preventing it.
However, senior leaders shouldn’t have to make this choice alone, unaided by Congress.
Conclusion
Legislators on both sides of the aisle have a responsibility to the military as well as to the country to fulfill their constitutional role in war-making. They should remove the U.S. military from its dangerous current position as the last barrier to unconstitutional war. Congress needs to pull the purse strings tight when it is being circumvented, pass veto-proof legislation prohibiting war against U.S. allies, exercise its legislative power to either approve war when in the national interest or prohibit it when it’s not, reform the 9/11 Authorization for Use of Military Force and generally do its job to implement constitutional design. The Constitution’s war-powers architecture makes the military a servant of the people. The decades-long erosion of this scheme risks the military becoming the exclusive tool of the executive branch … and thereby risks our democracy.
Rachel E. VanLandingham is a retired Air Force officer. She is the Irwin R. Buchalter professor of law and associate dean for research at Southwestern Law School in Los Angeles. She teaches criminal law, national security law, and the law of war. She is also president emerita and current director of the National Institute of Military Justice. In the Air Force, she served as a judge advocate, including tours at U.S. Central Command headquarters and as an appellate advocate. She is co-author of Military Justice: Cases and Materials (Carolina Academic Press 3d ed., 2020).
Image: Nano Banana
