President Donald Trump at the White House, March 2. Going to war is the most consequential decision a country can make. Wars are easier to start than end. Nasty surprises are inevitable. And as the military adage popularized by former Defense Secretary Jim Mattis goes, the enemy gets a vote. Few wars end quickly and decisively. Many last longer than expected, as their strategies and goals evolve in response to the enemy's unanticipated capabilities and resilience. Wars always test countries and rarely leave them unchanged.
In a republic, which depends on popular consent, the government has to create and sustain public support for the wars it enters. Every successful wartime president has done so. The presidents who didn't -- Lyndon B. Johnson and George W. Bush, for example -- left office with their goals unmet. By contrast, Franklin D. Roosevelt knew he couldn't move the U.S. to enter World War II on Britain's side until the American people were ready to go with him.
When the U.S. enters a war, it must be more than the president's war, or even the government's war. It must be the people's war as well. Involving the people's representatives in the decision is more than a constitutional nicety; it's a key ingredient of success. So is persuading the people that the war will serve the country's interests -- and their own.
The U.S. Constitution entrusts Congress with the power to "declare war." This doesn't mean Congress must authorize every use of American power, however restricted in scale and time. In the post-World War II era of standing armies, presidents enjoy substantial freedom of action in military affairs. But when a substantial portion of America's military might is to be invested in a conflict of extended or uncertain duration, a president shouldn't proceed without the consent of Congress and the people.
The last time Congress formally declared war was in June 1942. Since then, presidents have often sought and received congressional authorization for the use of military force in response to specific threats, actual or alleged. LBJ used the Tonkin Gulf resolution, which Congress overwhelmingly supported, to widen the war in Vietnam. Before initiating military action to expel Iraqi invaders from Kuwait, President George H.W. Bush obtained both a supportive United Nations Security Council resolution and explicit authorization from Congress. Before the invasions of Afghanistan and Iraq, President George W. Bush sought and received congressional resolutions authorizing the use of military force.
As this list shows, congressional involvement in war making doesn't guarantee good judgment. But it does compel the president to offer a public rationale for the deployment of military force, and it gives Congress the opportunity to scrutinize the president's claims.
In carrying out the latest military strikes against Iran, President Trump chose to bypass Congress and the American people. In his 2026 State of the Union address, he asserted his resolve to prevent Iran from obtaining nuclear weapons, as prior presidents had done, and expressed, as they also had, his preference for achieving this goal diplomatically.
This strategy of avoidance might have been politically viable if the American people already supported war with Iran. But they didn't before the onset of hostilities, and they don't now. Recent surveys from CNN and Reuters/Ipsos show that a minority of Americans approve of the U.S. decision to take military action in Iran. More than 6 in 10 believe that continuing it requires congressional authorization. In response, Mr. Trump told the New York Post that he doesn't care about the polls.
Meanwhile, confusion about the attack's ends and means is widespread. Although the president has made it clear that replacing Iran's clerical regime is a key goal, Defense Secretary Pete Hegseth said Monday that "this is not a so-called regime change war." Until this week, it seemed that to avoid even the appearance of repeating the war in Iraq, the U.S. would confine its operation to air and naval actions. But in remarks on Monday, Mr. Trump refused to rule out introducing ground forces into the battle.
The American people can be forgiven for wondering whether this is the best formula for avoiding another Iraq. On the other hand, as many scholars and military officers have pointed out, it's hard to find an example of regime change brought about without boots on the ground.
Eliminating Iran's threat to American interests in the Middle East was never going to be easy, even under the best conditions. By bypassing Congress, ignoring public sentiment and failing to articulate a clear vision of America's strategy and objectives, Mr. Trump has made a hard job even harder.