Summary
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 tshe 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.