The Volokh Conspiracy
Mostly law professors | Sometimes contrarian | Often libertarian | Always independent
President Trump Doesn't Need Congressional Approval for His Actions as to Iran
Congress can only stop Trump’s actions in Iran by passing a concurrent resolution of both Houses over Trump’s veto, or by declining to fund the war in next year’s budget.
President Donald Trump is taking a lot of heat for the military operations he launched unilaterally as Commander in Chief of the U.S. armed forces against the Iranian pirates/terrorists: (1) striking Iran militarily, (2) closing the Strait of Hormuz to Iranian oil exports, and (3) aiming (I expect successfully) to force Iran into capitulation. In fact, what President Trump is doing today with Iran is nothing more than a long overdue exercise of U.S. military power, of the sort that Presidents Thomas Jefferson and James Madison engaged in, without congressional approval, against the Barbary Pirates from 1801 to 1815.
The Barbary pirates were an early 19th century analog of the modern-day Iranian terrorist regime. They preyed on American and European trading ships and enslaved their crews. It is estimated that over 1 million American and European sailors were sold into slavery by the Barbary pirates during the centuries in which they preyed on American and European shipping. Robert Davis, British Slaves on the Barbary Coast, BBC (February 17, 2011). The Barbary pirates sailed out of Libya and North Africa generally until France conquered Algeria in 1830.
Congress never declared war against the Barbary pirates, but Presidents Jefferson and Madison rightly used their executive Commander-in-Chief powers unilaterally to cause American ships and marines to subdue them with the use of U.S. armed force. This defeated the Barbary pirates, and the Framing generation, which was still mostly alive from 1801 to 1815, acquiesced in the constitutionality of this unilateral presidential use of military force. The United States has fought only five declared wars in our history since 1789—the War of 1812, the Mexican American War, the Spanish-American War, World War I, and World War II. But U.S. Presidents, acting as Commanders in Chief, have unilaterally deployed our armed forces many other times.
Presidents have deployed the U.S. military without congressional permission on at least 125 occasions like the one that subdued the Barbary Pirates (1801-1815). Some of those engagements have been quite bloody such as the Korean War (33,700 deaths in battle), the Vietnam War, for which congressional authorization was withdrawn from 1971 to 1975 (3,246 deaths in battle), and the overthrowing of Libyan dictator Muammar Gaddafi by President Obama, in 2011 (4 deaths including of a U.S. Ambassador). These engagements were not authorized but were paid for by Congress. John C. Yoo & Robert J. Delahunty, The President's Constitutional Authority to Conduct Military Operations Against Terrorist Organizations and the Nations that Harbor or Support Them. In addition, the U.S. has fought four undeclared wars with congressional authorization in my lifetime: the Vietnam War (1964-1971), the Gulf War (1991), the Afghan War (2001-2021), and the Iraq War (2003-2011). The gloss of history on the constitutional text supports everything that President Trump is now doing.
It is settled constitutional law after 237 years of practice that presidents have the power to use the U.S. military without Congress's permission to subdue pirates, and terrorists, like the now dead Ayatollah Ali Khamenei who was quite simply a modern-day pirate. Iran has been a huge problem for the U.S. since its Islamic Revolution in 1979.
Iran captured and held hostage the U.S. Ambassador to Tehran and more than 50 American embassy personnel from November 1979 to January 20, 1981. It killed 241 U.S. Marines with a terrorist attack on a U.S. military base in Lebanon on October 23, 1983. And for the last half-century, Iran has funded a host of Islamic terrorist organizations throughout the Middle East including Hezbollah (in Lebanon), Hamas (in the Gaza Strip), and the Houthis (in Yemen), all of which have attacked Israel and Saudi Arabia, who are American allies, as well as attacking U.S. military personnel in the Middle East.
The Ayatollah Khamenei appeared to be planning to destroy Israel with a nuclear weapon, and Iran has been developing ballistic missiles that could hit Europe today and eventually, perhaps, the United States. The Ayatollah Khamenei routinely led crowds that denounced America as the "Great Satan" and led chants of "Death to America." Continuing to kick the can of dealing with Iran down the road as a problem was unwise behavior on the parts of the second President Bush, President Obama, and President Biden.
President Trump is the first President since 1979 who has had the guts to stop Iranian terrorism, which is a modern-day form of piracy in the Strait of Hormuz, a critical chokepoint in the global oil supply. He should be loudly praised for doing so. The American blockade on Iranian oil exports is likely to eventually cause Iran to surrender unconditionally, which will cause the much-needed end of Iran's nuclear program and its efforts to charge tolls for ships passing in international waters off the Strait of Hormuz (something Iran of course has no right to do). China's Xi Jinping agreed at the just-concluded summit with President Trump that (1) Iran could not be trusted to have nuclear weapons, (2) Iran cannot charge tolls on ships passing through the Strait of Hormuz, and (3) Iran should immediately end its blockade of shipping in the Strait of Hormuz. The two most powerful militaries on earth are in complete agreement here.
When regime change happens in Iran, as I expect it will if the U.S. persists, the U.S. can help Iran to pump much more oil and natural gas, as the U.S. is now trying to do in Venezuela having seized former Venezuelan President, Nicholas Maduro. And when that happens oil prices will likely tumble to $40 a barrel or so, which may cause Vladimir Putin's vicious and corrupt regime to end in Russia, thus ending the Ukrainian War on terms favorable to Ukraine. Americans need to be patient and to give the blockade time to work. Iran cannot live without 90% of its budget, which comes from oil and gas sales in the long run.
The Constitution says that the executive power shall be vested solely in the President, as is the Commander-in-Chief power. From President George Washington's use of the army to put down the Whiskey Rebellion, to President Jefferson's and Madison's use of the navy and marines to put down the Barbary Pirates, to President Abraham Lincoln's use of the army and navy to win the Civil War, to President Harry Truman's use of the U.S. military to win the Korean War, to President Barack Obama's use of our air force to overthrow the terrorist regime of Muhammar Gaddafi in Libya, we Americans have from the outset construed presidential war powers to generally allow the President to take military action without prior congressional approval to put down terrorist threats or threats from pirates.
Congress's powers to (1) declare war and (2) grant letters of marque and reprisal are powers to trigger the international treaty obligations of our allies as a matter of international law, and to grant privateers the power to seize enemy ships as prizes. They do not block the President from commanding armed forces to engage in the behavior discussed above. It would be unconstitutional for one or both of Houses of Congress to pass an Act to stop the Iran hostilities, given that the President alone has the executive power, which includes the Commander-in-Chief power. For more on the constitutional arguments in this post, see Robert Delahunty & John Yoo, Making War, 93 Cornell Law Review 123 (2007), as well as their other writings on presidential war power.
Congress could, of course, constitutionally stop what President Trump is doing by cutting off funding for military actions related to Iran. But, for the practical reasons given above, this would be a foolish thing for Congress to do. Yes, domestic gas prices are temporarily high right now. But if President Trump sticks with the blockade, we will likely get regime change in Iran, and much lower oil and gas prices very quickly for the foreseeable future. Still, Congressional restriction of funding, unwise as it may be, would at least be within Congress's powers; a Congressional Act purporting to order the President to stop hostilities or to prematurely end the blockade would be outside Congress's powers. And it would wrongly end an important struggle with a group of pirates and thugs who do not have the support of the Iranian people.
Facts Only
President Donald Trump has taken unilateral military actions against Iran, including strikes and a blockade of the Strait of Hormuz.
The article compares these actions to historical precedents, such as Presidents Jefferson and Madison’s campaigns against the Barbary Pirates (1801–1815).
The U.S. has fought only five declared wars in its history but has engaged in numerous undeclared military operations without congressional approval.
Examples of unilateral presidential military actions include the Korean War, Vietnam War, and the 2011 overthrow of Libyan dictator Muammar Gaddafi.
Iran has a history of hostile actions against the U.S., including the 1979–1981 hostage crisis and the 1983 bombing of a U.S. Marine barracks in Lebanon.
Iran supports terrorist groups like Hezbollah, Hamas, and the Houthis, which have targeted U.S. allies and personnel.
The article claims that Iran’s nuclear ambitions and blockade of the Strait of Hormuz justify Trump’s military response.
China’s Xi Jinping reportedly agreed with Trump at a summit that Iran should not have nuclear weapons or control shipping in the Strait of Hormuz.
The article argues that the president’s Commander-in-Chief authority allows unilateral military action without congressional approval.
Congress could defund the operations but cannot legally block them through legislation.
The piece suggests that regime change in Iran could lead to lower oil prices and destabilize Russia’s economy.
Historical examples cited include Lincoln’s Civil War actions and Truman’s Korean War interventions.
Executive Summary
President Donald Trump has taken unilateral military actions against Iran, including strikes, a blockade of the Strait of Hormuz, and efforts to force Iranian capitulation. The article argues that these actions are constitutionally justified, drawing parallels to historical precedents like Presidents Jefferson and Madison’s campaigns against the Barbary Pirates without congressional approval. It claims that U.S. presidents have frequently deployed military force without congressional authorization, citing examples such as the Korean War, Vietnam War, and the 2011 intervention in Libya. The piece frames Iran as a modern-day pirate state, highlighting its history of hostage-taking, support for terrorist groups, and nuclear ambitions. It asserts that Trump’s blockade of Iranian oil exports could lead to regime change, lower global oil prices, and destabilize adversaries like Russia. The constitutional argument hinges on the president’s role as Commander-in-Chief, with Congress’s powers limited to funding or defunding military actions rather than directly halting them. The article also references a summit where China’s Xi Jinping allegedly agreed with Trump on curbing Iran’s nuclear and maritime ambitions.
The analysis presents a libertarian-leaning perspective, emphasizing executive authority and downplaying the need for congressional oversight in military engagements. It acknowledges that Congress could defund the operations but argues this would be unwise. The piece assumes that regime change in Iran would benefit U.S. interests, including energy markets and geopolitical stability. However, it does not address potential counterarguments, such as the risks of escalation, international legal concerns, or the historical consequences of unilateral military actions.
Full Take
This article presents a strong libertarian case for expansive executive war powers, framing Trump’s actions against Iran as constitutionally sound and historically consistent. The steelman version of this narrative is compelling: it cites well-documented historical precedents, such as Jefferson’s Barbary Wars, to argue that presidents have long exercised unilateral military authority. It also leverages geopolitical logic, suggesting that Iran’s destabilizing behavior—nuclear ambitions, support for terrorism, and maritime aggression—justifies decisive action. The piece effectively ties these actions to potential benefits, such as regime change, lower oil prices, and even the weakening of Russia.
However, the analysis exhibits several patterns worth scrutinizing. First, it engages in **ARC-0024 Ambiguity** by conflating historical examples (e.g., the Barbary Wars) with modern geopolitical complexities, ignoring key differences in scale, international law, and congressional oversight. Second, it employs **ARC-0043 Motte-and-Bailey**, asserting that the president’s actions are merely "subduing pirates" (a narrow, defensible claim) while advocating for regime change and broader military engagement (a far more controversial position). Third, the piece uses **ARC-0012 Appeal to Authority**, citing legal scholars Yoo and Delahunty without acknowledging countervailing constitutional interpretations or the risks of unchecked executive power.
The root cause of this narrative is a libertarian-leaning interpretation of presidential power, prioritizing executive agility over democratic checks. It assumes that unilateral action is inherently more effective than congressional deliberation, a debatable premise. The implications are significant: if this logic holds, future presidents could justify extensive military interventions without oversight, potentially eroding constitutional balance. The piece also overlooks the human costs of escalation, such as civilian casualties or regional instability.
Bridge questions: What constitutional safeguards, if any, should limit presidential war powers in the 21st century? How might Iran’s allies (e.g., Russia, China) respond to prolonged U.S. military pressure, and what second-order risks does this pose? Would the same arguments apply if a future president took unilateral action against a different adversary, such as North Korea or Venezuela?
Counterstrike scan: If this were part of a coordinated influence campaign, the playbook would involve framing the president’s actions as both legally unassailable and morally urgent, while dismissing opposition as naive or obstructionist. The actual content aligns with this pattern but does not appear overtly manipulative; it is more a reflection of a consistent ideological stance than a deceptive operation. The lack of counterarguments and selective historical framing are notable but not necessarily malicious.
Sentinel — Human
This text is a polemical argument blending historical analogy, legal theory, and geopolitical prediction to advocate for a specific interpretation of presidential military authority and a policy strategy regarding Iran.