Dispute between US President and Congress regarding War Powers: Background and Horizons

Amr Abdel-Aty | 04 Feb 2020

President Donald Trump’s order to assassinate Qasem Soleimani, commander of the Quds Force of the Iranian Revolutionary Guard, on January 3, 2020 has reignited debate between Congress and the President as to who should have the final say in the use of US military power abroad. The debate escalated when the Democrats won a majority in the House of Representatives in the congressional mid-term elections on November 6, 2018, following which they have taken various steps, with the support of several Republican lawmakers, to restore the constitutional power of the legislature to declare war and to control the movement of US troops abroad. For many years, these powers have been relinquished to successive presidents, who have expanded their office’s war powers and have embroiled the US army in international conflicts that have ended up costing more than they were worth.

In the aftermath of Soleimani’s death, and in the light of fears that escalation between the United States and Iran could lead to a military confrontation, a number of Democratic lawmakers submitted bills, backed by several Republican members of Congress, aimed at limiting President Trump’s authority to implicate Washington in a war with Tehran. At the same time, both chambers of Congress have sought to impose more control over military operations launched pursuant to the two congressional mandates issued in 2001 and 2002, which authorized President George W. Bush Jr to use US military power abroad. Some Democrats vying to run as the Democratic candidate in the November 2020 presidential elections have called for these mandates to be cancelled.

Background and context

The US political system is, at heart, based on the principle of checks and balances, whereby the Constitution distributes powers between the three branches (legislative, executive, and judicial) in such a way as to prevent any of one of them from making a unilateral decision. The relationship between these three branches is based not simply on the separation of powers, but rather on the concept of separate institutions that share powers. This has created a historical conflict between the President and Congress regarding many areas of authority, in particular the authority to declare war, i.e. the ability to declare war or order military engagement in a foreign conflict. The Constitution provides that Congress has the power to declare war, as well as “authority over the pursestrings”, meaning the authority to allocate funds to wage war (art. 1, sect. 8). At the same time, however, the Constitution stipulates that the president is the commander-in-chief of the armed forces (art. 2, sect. 2). This means that the President is responsible for implementing the decision to go to war. In other words, if Congress is responsible for declaring the start and end of a war, then the president is responsible for managing the war once it has been authorized.

Although there is an explicit provision in the Constitution underscoring that Congress must be able to control the president’s ability to deploy troops outside US territory, there is consensus that the authority to implement a decision to go to war allows the president to direct military forces at times of attack or imminent threat, such as for the purpose of self-defense. In reality, previous experience of wars fought by Democrat and Republican presidents alike reveals that they were able to circumvent Congress’s authority to declare war, without requiring the authorization of Congress and without resorting to self-defense provisions.

Years after the legislature ceded its constitutional authority to declare war to the executive branch, which has embroiled US troops in numerous military conflicts since World War II, in 1973 Congress passed the War Powers Act to restore its role in the decision to wage war and to force the president to obtain a mandate from Congress before interfering in an external conflict or possible hostilities.

The Act provides that, in the event that US forces are deployed to engage in hostilities abroad, the president must inform Congress within 48 hours, and if the legislature does not formally approve such action, the president must return the troops to US territory within 60 days. The Act grants the president an additional 30 days if there is a “military necessity” to extend the deployment. The Act excludes certain situations in which the president can unilaterally order the use of force without first having to consult Congress, including situations in which the president has prior legal authorization to order military intervention abroad or where a state of emergency has been declared in response to an attack against US territory or armed forces.

Although some US presidents have relied on the War Powers Act to respond to threats against the United States and its citizens, such as when President Jimmy Carter attempted to use military force to free American hostages held at the US embassy in Tehran in 1979, in reality most presidents have, on more than one occasion, unilaterally made the decision to go to war without consulting Congress, either by forging international alliances or by relying on UN Security Council resolutions authorizing them to go to war outside US territory. Most recently, US forces participated in an international coalition that led military operations against Libyan Prime Minister Muammar al-Gaddafi in 2011 without the approval of Congress. President Barack Obama referred to Security Council resolution 1973 (2011) to justify the participation of US troops.

Current controversy over “power to declare war”

There has long been debate within the United States as to whether the president or Congress should have the final say in declaring war and mobilizing US troops to participate in external conflicts. This debate has intensified over the past decade, however, after the 2001 Afghanistan and 2003 Iraq wars, which were costly both financially and in terms of human lives. While these wars were mandated by the legislature, they did nothing to achieve stability and security in either country, but rather increased their vulnerability. Democratic President Obama and Republican President Trump both treated the 2001 and 2002 mandates as a “blank check” to launch foreign wars, and they extended the mandates to justify the use of military abroad.

This controversy has been fueled by the political polarization witnessed in the United States since President Trump’s victory in the November 2016 presidential elections and by the growing fears that the escalating tensions between the United States and Iran since Washington’s withdrawal from the 2015 nuclear agreement, in accordance with its strategy of “extreme pressure”, and the assassination of Quds Force Commander Qasem Soleimani earlier this year could lead to a war in the Middle East that has not been authorized by Congress and to which most lawmakers and US citizens would be opposed. At the same time, there is growing talk of the idea that the Middle East region is declining in importance, given that the main challenge facing the United States now lies in the revisionist powers within the international system (Russia and China) and the threat that they pose to US interests and leadership under the current system.

Current debate in the United States is divided into two camps on the question of whether the president should be able to use military force abroad without first consulting Congress, which wants to restore its constitutional role and powers in war decisions in order to prevent the executive branch from making unilateral decisions regarding the use of military force abroad and to prevent US forces from engaging in conflicts abroad without first obtaining a mandate from the legislature:

One side of the debate argues that the president does not have the right to use military force abroad without congressional approval. Those on this side of the debate are calling for more restrictions on the president’s powers, in particular in the light of the decisions taken by former President Obama and current President Trump to engage US military forces in hostilities abroad without the approval of Congress. They argue that President Trump’s use of military force in the Middle East does not comply with the congressional mandate granted to former President George Bush Jr in 2001, which authorized him to use military force against the individuals and organizations responsible for planning and facilitating the attacks on September 11, 2001, and for harboring or training terrorists, nor the 2002 mandate authorizing him use military force against Iraq in order to protect the United States against the threat that it posed. In justifying the assassination of Qasem Soleimani, President Trump relied on the 2002 mandate and on the president’s constitutional authority to take military action to defend the United States and its citizens.

Several US officials, led by president Trump, justified the assassination as an act of defense. According to a statement by the Pentagon, Soleimani was assassinated in order to protect US troops and citizens in Iraq and the Middle East, particularly as the Hezbollah Brigades and other militias loyal to Iran had been targeting military bases at which US troops and diplomats were stationed, as well as the US embassy in the Green Zone.

Rebutting the claim that the president had the authority to order the assassination of Soleimani pursuant to article 2 of the Constitution, opponents argue that the article applies only in very limited circumstances, namely in the event of an imminent attack, which was not the case with Soleimani. They also argue that the threat that Soleimani and Iran posed to US interests, troops, and citizens in the region was not new, meaning that the president had ample time to obtain a mandate from Congress before using military force abroad.

On the other hand, however, supporters of the president’s actions argue that the president has the right to use military force abroad in order to protect the United States’ national security, its interests, and its citizens abroad, even where he has not obtained a congressional mandate. They reject claims by members of Congress that US troops are participating in hostilities outside US territory, in particular hostilities taking place in or affecting Yemen. They assert that President Trump’s use of military force in the Middle East complies with the congressional mandates granted to President Bush in order to combat terrorism abroad and protect US interests and national security in the Middle East.

Since its adoption in 1973, the War Powers Act has been viewed by most US presidents as an unconstitutional violation of the powers granted to the president, as commander-in-chief of the US army, by the Constitution. Similarly, President Trump believes that the bills under discussion by Congress aimed at curbing his right to use military force abroad would interfere in his constitutional authority as supreme commander of the armed forces and would weaken the ability of US military to manage military clashes effectively and efficiently and to withdraw in an orderly and timely manner.

President Trump and members of his administration argue that attempts by Congress to undermine the president’s authority to control the movement of US troops abroad and to use military force against US opponents undermines the administration’s efforts to combat the spread of terrorist and extremist organizations such as Al-Qaida and Islamic State, not to mention encouraging Iran’s malicious behavior in Yemen and its role in undermining stability and security in the Middle East and embolden opponents of the United States to threaten US interests and to target US citizens and troops around the world. In his letter vetoing the joint decision of the House of Representatives and the Senate to withdraw US combat troops stationed in Yemen, President Trump stated that such a decision limited his authority to protect the lives of more than 80,000 US citizens living in countries involved in the coalition, as Iranian-backed Houthis were using missiles, drones, and bomb boats to target civilian and military areas within zones designated for US citizens.  

Attempts by Congress to restore its constitutional powers

Since winning a majority in the House of Representatives in the 2018 congressional mid-term elections, the Democrats have been working vigorously, as part of their opposition to President Trump’s foreign policy, to restore the constitutional authority of the legislature to declare war and to authorize US troops to engage in external conflicts. The most important efforts taken to that end are as follows:

First, the Democrats have submitted bills to both chambers of Congress (the House of Representatives and the Senate) aimed at undermining the president’s ability to use military force without consulting Congress, and calling for the withdrawal of US troops from conflict areas abroad. In April 2019, US lawmakers passed a joint bill (S.J.Res.7) to withdraw US troops from hostilities taking place in or affecting Yemen. On March 13, 2019, the Senate adopted the bill by 54 votes to 46, and on April 4, the House of Representatives adopted it by 247 votes to 175.

As many US lawmakers are worried that the United States may find itself engaging in an unwanted war with Iran without the consent of Congress, following the assassination of Soleimani and the escalation of US–Iranian tensions since May 2019 as a result of the United States’ strategy of “maximum pressure” and Iranian resistance, both chambers of Congress have begun to discuss the bills submitted by Democratic members, which are supported by several Republicans, aimed at limiting the president’s authority to take military action against Iran.

Second, drawing on the “authority over the pursestrings” held by Congress, bills have been submitted to prohibit the US administration from spending any money on military action abroad without the approval of Congress or where not provided for by the 1973 War Powers Act. As the cost of war is high, the executive branch’s inability to finance a war or military action would prevent it from taking place.

Third, Democrats are making efforts to cancel the 2001 and 2002 mandates granted directly to the Bush administration, which authorized President Bush to use military force abroad without consulting Congress. As they are facing difficulties in achieving this, some Democrats have proposed imposing greater control over the president’s use of military force pursuant to those mandates. Alternatively, others have proposed issuing a new mandate to allow the president to use military force in accordance with strictly defined purposes and time limits, as the two previous mandates were not time-limited, thereby allowing President Obama and President Trump to use them to justify military action in the Middle East.

Obstacles faced by Congress

The biggest difficulties that the legislature is facing in its attempts to restore the constitutional authority that it ceded to the president many years ago, thereby authorizing the president to unilaterally take the decision to go to war or to deploy military forces abroad without the permission of Congress, is the difficulty of passing a binding law that would limit the president’s ability to use military force without consulting Congress. While any such bill would need to be adopted only by a simple majority in both chambers of Congress, the president has the right to veto the bill. Congress must then vote by a two-thirds majority to override the president’s veto if the bill is to become law.

This was the case in April 2019 when both chambers of Congress approved the joint bill calling for the withdrawal of US troops from hostilities taking place in or affecting Yemen. While the bill was passed by a simple majority in both chambers, on April 16 President Trump used his constitutional power of veto to oppose the decision. As the bill did not receive the support of two thirds of lawmakers, it was not adopted and therefore did not become binding.

Although Congress did not succeed in overriding the president’s veto, it nonetheless sent a message to President Trump that it was the legislature, and not he, that was authorized to declare war and to mandate US troops to participate in combat outside the United States.

Many presidents have overridden Congress’s authority to declare war and to mandate the deployment of US troops abroad, on the grounds that they were authorized to unilaterally order the use of military force in response to threats against the United States or any of its citizens, that the use of military force does not constitute a war in the constitutional sense, and that their military actions fell short of being “hostilities” as defined by the law. Instead of seeking congressional approval before using military force or implicating US troops in a foreign conflict, many presidents have instead taken unilateral action and have formed a team of legal advisers to defend their actions and their failure to adhere to the provisions of the Constitution and the 1973 War Powers Act.

Furthermore, the 1973 War Powers Act contains two major loopholes that allows the president to take military action abroad without the approval of Congress. First, the president can unilaterally conduct military action for 90 days without the approval of Congress, provided that he informs Congress of such action within 48 hours of its launch. Second, the president can go to war without informing or consulting Congress as required by the Constitution and the War Powers Act if he forms an international alliance or if he is implementing a Security Council resolution that authorizes the United States to go to war outside its territory.


The conflict between the president and Congress over war powers is historic. On more than one occasion, the legislature has ceded its constitutional rights to the executive branch so that the president can unilaterally take the decision to go to war. As such wars have failed to achieve their goals and have cost the United States dearly, Congress is attempting to restore its constitutional role in declaring war and in authorizing US military forces to engage in hostilities abroad.

In spite of repeated attempts by current members in both chambers of Congress to restore that authority, they have faced numerous obstacles. As a result, the president still retains the final say on all such decision, particularly given the reluctance of the judiciary to rule on disputes between presidents and Congress regarding war powers.


* Egyptian researcher specializing in US affairs.


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