In the wake of the Democratic Party taking control of both chambers of Congress, Vice President J.D. Vance wrote on X that he believes voters chose to give control of Congress to Democrats because of the Iran war. According to an October survey by the Pew Research Center, around two-thirds of Americans disapprove of the way the war with Iran is being handled.
Can the new Congress do anything about the ongoing war? We've previously written about how U.S. presidents do not have authority to declare war, although presidents have long claimed authority to conduct military operations without congressional authorization. The U.S. has been in direct conflict with Iran for over 8 months without that authorization. President Donald Trump told reporters the day after the U.S. midterm elections that while the Iran war may be unpopular, “the Iran thing we had to do, and we continue to do it.”
With the war still unresolved, what options does Congress have? Here are some potential avenues for the House and Senate when members take office in January 2027.
War Powers Resolutions
Congress could pass a joint resolution directing President Trump to end unauthorized U.S. hostilities against Iran and setting a deadline for withdrawing U.S. forces. Under the War Powers Resolution of 1973, the Senate could use expedited procedures to bring a qualifying joint resolution to a vote, while the House would consider it under its ordinary procedures.
However, a joint resolution goes to the president, who could veto it. To override a veto, Congress would need a two-thirds majority in each chamber. Even with majorities in both chambers, Democrats could struggle to secure enough votes to override a veto.
Instead of a joint resolution, Congress could pass another concurrent resolution. The 1973 law specifically allows for this. A concurrent resolution would not be subject to a veto.
But …
Congress has already tried both approaches. In 2026, it passed a concurrent resolution with bipartisan support directing Trump to remove U.S. armed forces from hostilities against Iran unless Congress authorized them. The House passed it on June 3, and the Senate agreed on June 23.
However, a concurrent resolution cannot compel withdrawal because it is not presented to the president. In INS v. Chadha (1983), the Supreme Court held a one-house legislative veto unconstitutional because it violated the Constitution’s requirements for passage by both chambers and presentation to the president. Although the case did not directly address war-powers resolutions, its reasoning undermines using a concurrent resolution to require withdrawal.
A joint resolution avoids that constitutional problem but still faces a presidential veto. In 2020, after the U.S. killed Qassem Soleimani, Congress passed S.J.Res. 68, directing an end to unauthorized U.S. hostilities against Iran. Trump vetoed it, and the Senate failed to override his veto.
Previous Attempts at Limiting Presidential War Powers in Court
Under the War Powers Resolution, the president generally must end U.S. military involvement in hostilities within 60 days unless Congress authorizes it to continue. The president can take up to 30 additional days to withdraw the troops, but must explain to Congress in writing why military necessity requires that extra time to bring them home safely.
Regardless of any new measures, it could be argued that President Trump has already violated the War Powers Resolution. However, the Trump administration has previously maintained that a ceasefire ended the relevant hostilities or stopped the statutory clock, although these positions are also disputed.
No automatic enforcement mechanism makes a president stop when the deadline expires.
This has happened before. Members of Congress have previously challenged presidents' ability to continue hostilities against foreign countries in court. However, these lawsuits have run into several procedural or constitutional barriers that prevent courts from hearing them.
- In Crockett v. Reagan, 29 members of Congress challenged U.S. military involvement in El Salvador, but courts dismissed the challenge as nonjusticiable.
- In Lowry v. Reagan, House members alleged that President Reagan had failed to submit required war-powers reports concerning Persian Gulf tanker-escort operations and an attack on an Iranian naval vessel. The court dismissed the case, concluding that Congress and the president should resolve the dispute. It did not decide whether Reagan was required to submit the reports.
- In Campbell v. Clinton, 31 members of Congress challenged President Clinton's air campaign in Yugoslavia, but an appeals court upheld the dismissal for lack of standing. The court held that Congress had legislative tools to oppose the operation.
This does not mean legal action is impossible. Congress could authorize a lawsuit on its own behalf alleging injury to its constitutional powers, rather than leaving individual members to sue. But institutional authorization would not guarantee standing, a favorable ruling on the merits, or an order ending hostilities.
Funding
A separate option could involve the power of the purse. Under the U.S. Constitution, Congress controls federal spending. Theoretically, Congress could prohibit spending on military operations in Iran, perhaps by attaching funding restrictions to a defense appropriations bill or another funding measure.
That legislation could also face a veto. Congress could gain leverage by including the restrictions in a spending package the administration wants, refusing to approve additional funding, or both.
If Congress refuses to approve additional funding, the president cannot veto Congress' refusal to pass a bill. However, existing appropriations could still support operations. Restrictions would also need careful drafting to prevent the Trump administration from using existing statutory authority to transfer money to military operations in Iran.
The president's role as commander in chief gives the executive branch authority over military command and operations. But Congress has substantial constitutional authority over military funding and regulation, including the power to restrict funding for a conflict. The exact boundary between what Congress can restrict and what interferes with the president's constitutional authority is a gray area.
Impeachment
The House could consider impeachment if members believe the president has committed an impeachable offense. But impeachment alone would not remove him: Conviction requires a two-thirds vote of senators present. Trump was impeached twice during his first term and acquitted by the Senate both times. Congress could also attempt to impeach Secretary of Defense Pete Hegseth, but could not simply reverse his confirmation or pass a resolution demanding it. Impeachment also requires "Treason, Bribery, or other high Crimes and Misdemeanors," not just incompetence, and Hegseth's removal would not necessarily end the war.
So What Now?
Winning control of Congress gives Democrats more leverage, but it does not mean they can force Trump to end the war. They could pass legislation requiring U.S. forces to withdraw or restricting money for military operations, but Trump could veto either. They could also refuse to approve more funding, though existing money could keep operations going.
Ultimately, their ability to end U.S. involvement will depend on whether they can build enough support to get binding restrictions into law.
