War between the United States and Iran looms, even though the latter poses no threat to the former. President Donald Trump says he doesn’t want war but for the Iranians to call him. Perhaps his entire campaign is an elaborate effort to scare Tehran to the negotiating table. Or perhaps he hopes to win political support by fomenting a foreign crisis. How ironic that would be: in 2011, Trump warned via tweet that “Barack Obama will attack Iran in the not too distant future because it will help him win the election.”

However, the president already ran against the Islamic Republic, in 2016. Moreover, his words have been incendiary, threatening “the official end of Iran.” Although U.S. intelligence officials admit that Tehran’s confrontational rhetoric is largely a response to Washington’s aggression, the administration’s military moves are sharply increasing tensions as well as the possibility of a costly mistake or misjudgment.

The War Party is active again in the Imperial City. Before joining the administration, National Security Advisor John Bolton forthrightly called for an attack on the Islamic Republic. Secretary of State Mike Pompeo also demanded regime change in Iran. More recently, he admitted that sanctions were intended to induce the Iranian people to “change the government.” While claiming not to seek war, he threatened retaliation for any attack by Iranian “proxy forces” and on “American interests.”

Tehran has long been a favorite target of influential neoconservatives and ultra-hawks. The invasion of Iraq almost immediately led to calls for a turn to Tehran. Several years ago, Patrick Clawson of the Washington Institute of Near East Policy suggested staging a false flag operation: if “the Iranians aren’t going to compromise,” he said, “it would be best if somebody else started the war.” Today, Senator Tom Cotton predicts an easy American victory.

The Saudis also openly favor an American war against Iran. (Defense Secretary Robert Gates once quipped that Riyadh would fight Iran “to the last American.”) A newspaper owned by the royal family last week called on Washington to “hit hard.” Israeli Prime Minister Benjamin Netanyahu has worked tirelessly to inflate the Iranian “threat” and told a TV interviewer that he’d convinced Trump to abandon the nuclear deal.

Yet conflict with Iran would be a disaster, far worse than with Iraq. Even the Council on Foreign Relations’ Max Boot, a vocal neoconservative and uber-hawk, has warned against this. And Americans would not be the only casualties. Jason Rezaian, The Washington Post reporter who spent more than a year in an Iranian prison, observed: “those who will suffer most have little say in the matter. It’s the Iranian people who have borne the brunt of 40 years of enmity between the United States and the Islamic republic, and in the current standoff, they stand to lose the most yet again.”

The possibility that the chief executive might rush or be pushed into such a disastrous war is exactly why the Founders obliged presidents to go to Congress for approval. The Constitution places the power to declare war in the hands of the legislature.

Yet modern presidents routinely claim monarchical powers, using the military without proper authority. Legislators often avoid taking responsibility for wars that might turn unpopular. But neither unconstitutional nor irresponsible behavior justifies chief executives doing the same.

Trump has proven no more faithful to the Constitution than his predecessors. For instance, Pompeo refused to commit the administration to going to Congress for the authority to attack Iran. (The secretary did the same when earlier questioned about the administration’s military threats against Venezuela.) Pompeo suggested that the president might rely on the post-9/11 authorization for use of military force, an even more ludicrous reach than the Obama administration’s appeal to the same measure for its fight against the Islamic State and strikes on Syria.

The refusal to obey the Constitution is evidence of weakness. In contrast, many of America’s strongest chief executives recognized Congress’s authority. George Washington declared: “The Constitution vests the power of declaring war with Congress; therefore no offensive expedition of importance can be undertaken until after they shall have deliberated upon the subject, and authorized such a measure.”

Abraham Lincoln praised the Founders for recognizing war “to be the most oppressive of all Kingly oppressions; and they resolved to so frame the Constitution that no one man should hold the power of bringing this oppression upon us.” Dwight Eisenhower was equally insistent on the need for legislative approval for war.

Delegates to the constitutional convention insisted they were not recreating the king of England or replicating his powers, especially to start wars. After all, war is the hallmark of unlimited government. Warned James Madison: “Of all the enemies of true liberty, war is, perhaps, the most to be dreaded, because it comprises and develops the germ of every other. War is the parent of armies; from these proceed debts and taxes; and armies, and debts, and taxes are the known instrument for bringing the many under the domination of the few.”

The Founders knew this problem well, since a succession of European kings and queens had launched a succession of unnecessary and even frivolous conflicts. The price was paid in blood and treasure by the common folk. John Jay observed that kings were often led “to engage in wars not sanctified by justice or the voice and interests of his people.” Pierce Butler insisted that the president not be invested with the authority to start wars, like a monarch who enjoyed the “opportunity of involving his country in a war whenever he wished to promote her destruction.”

Madison explained the principle incorporated in the Constitution: “Those who are to conduct a war cannot in the nature of things, be proper or safe judges, whether a war ought to be commenced, continued, or concluded. They are barred from the latter functions by a great principle in free governments, analogous to that which separates the sword from the purse, or the power of executing from the power of enacting laws.”

Thus, the Constitution gives to Congress most military powers: raising an army, funding the military, issuing letters of marquee, approving rules of war, ratifying treaties, and, of course, taking America into war. Article 1, Section 8 (11) states: “Congress shall have the power…to declare war.” Observed Madison: the “fundamental doctrine of the Constitution that the power to declare war is fully and exclusively vested in the legislature.”

Despite this history, some modern analysts bizarrely contend that Congress only ever gets to “declare” that the president had started a war. In fact, the Founders changed the operative word from “make” to “declare” merely to ensure that the commander-in-chief could respond to a surprise attack. They did not even believe the president could launch a reprisal without legal authority. They certainly didn’t intend to enable the president to wander the globe smiting nations hither and yon at his sole discretion.

Despite their many disagreements, the Founders agreed on this point. The president commanded the military but could only prosecute wars authorized by Congress. Said George Mason, the chief executive “is not safely to be entrusted with” the power to start wars, which required “clogging rather than facilitating war.” Thomas Jefferson cited the Constitution’s “effectual check to the dog of war by transferring the power of letting him loose.” Explained James Wilson: “It will not be in the power of a single man, or a single body of men, to involve us in such distress; for the important power of declaring war is in the legislature at large.”

Even Alexander Hamilton, who leaned toward monarchy, emphasized that the commander-in-chief was just the “first general and admiral.” The president’s authority was “in substance much inferior to” that of Britain’s monarch, and “would amount to nothing more than the supreme command and direction of the land and naval forces…while that of the British king extends to the declaring of war.”

Trump is bound by the Constitution when confronting Iran. Indeed, the not insubstantial possibility of him and his officials lying America into another irresponsible war of choice is why the Founders placed the decision with Congress. Americans have learned at a high cost that presidents cannot be trusted to act like kings.

With a presidential election approaching, Americans should seriously ponder whether they want to entrust the presidency to someone who believes he’s empowered to make war without constraint. It’s time to choose a chief executive who’s prepared to follow the Constitution.

Doug Bandow is a senior fellow at the Cato Institute. A former special assistant to President Ronald Reagan, he is the author of Foreign Follies: America’s New Global Empire (Xulon Press). He is a graduate of Stanford Law School and a member of the California and Washington, D.C. bars.