For several years,Yemen has been in a state of civil warbetween a Saudi-led coalition supporting the Yemeni Government and Houthi forces. The US armed forces are not directly engaged in Yemen but have been supporting Saudi military efforts with aerial targeting and intelligence sharing.

On 13 December 2018, the United States (US) Senate passedResolution S.J. Res. 54 115thCongress(Res.54) directing the US President to withdraw US Forces from hostilities in Yemen. Res. 54 provides (emphasis added):

This joint resolutiondirects the President to remove U.S. Armed Forces from hostilities in or affecting Yemen within 30 days unless Congress authorizes a later withdrawal date, issues a declaration of war, or specifically authorizes the use of the Armed Forces. Prohibited activities include providing in-flight fueling for non-U.S. aircraft conducting missions as part of the conflict in Yemen. This joint resolution shall not affect any military operationsdirected at Al Qaeda.

_The President mustsubmit to Congress, within 90 days, reportsassessing the risks that would be posed: (1)if the United States were to cease supporting operations with respect to the conflict in Yemen, and (2)if Saudi Arabia were to cease sharing Yemen-related intelligence with the United States.

_

Res. 54 has not yet been debated in the House of Representatives and currently has no legal force. However, it is an historic public message from the Senate: this is thefirst timesince theUS_War Powers Resolution_(WPR) was made in 1973 that a measure introduced to restrict a Presidents use of armed force has proceeded to a vote and passed either chamber of Congress.

TheLaw Library of Congressexplains the background to the_WPR_:

The Constitution of the United States divides the war powers of the federal government between the Executive and Legislative branches: the President is the Commander in Chief of the armed forces (Article II, section 2), while Congress has the power to make declarations of war, and to raise and support the armed forces (Article I, section 8). Over time, questions arose as to the extent of the President’s authority to deploy U.S. armed forces into hostile situations abroad without a declaration of war or some other form of Congressional approval. Congress passed the War Powers Resolution in the aftermath of the Vietnam War to address these concerns and provide a set of procedures for both the President and Congress to follow in situations where the introduction of U.S. forces abroad could lead to their involvement in armed conflict. …

U.S. Presidents have consistently taken the position that the War Powers Resolution is an unconstitutional infringement upon the power of the executive branch.

The_WPR_assertsthat the President has power to use the armed forces in hostilities, but only where there has been:

• a declaration of war
• specific statutory authorisation, or
• an attack on the US or its armed forces

According toDr Stephen Schwalbe, an academic at the American Public University, the_WPR_also requires:

• the President to consult with Congress before deploying armed forces abroad
• the President to provide written notification to the Congress within 48 hours of deploying armed forces abroad and
• all armed forces to be withdrawn after 60 days, unless there is a declaration of war or a Congressional joint resolution to continue military operations.

Despite disputing the constitutional validity of the WPR, Presidents since Nixon have generally chosen to formally advise Congress of deployments where force is likely to be used, but usually after some delay and deliberately not in response to the_WPR_requirements.

On 13 December 2018, the House of Representatives attached a procedural rule change to an importantAgriculture Improvement Billto ensure that there would be no expedited consideration of aHouse Resolutionalmost identical to Res.54. This does not defeat Res. 54 but suggests it islikely the resolution will be not considereduntil the next session of Congress commences in January 2019. Even if Res. 54 passes the House in the new year, President Trump has power to veto the Bill which would send it back to Congress for a vote tooverride the veto.To pass a bill over the President’s veto requires a two-thirds vote in each Chamber. Res. 54 was passed in the Senate by 56 votes to 41 so it is unlikely to achieve a two thirds vote. Even if Congress voted to override the veto,its next action is uncertain.

Althoughjudicial reviewof executive action is theoretically available, so far the US courts have not allowed judicial review of military deployment decisions and no congressional effort to hold the President accountable for breaching the_WPR_has succeeded. The only effectiveenforcement powerCongress has is to cut off funding for military operations completely or to remove the President from office. Both options are, in this context, almost unachievable for pragmatic political reasons._WPR_has therefore, not been effective as a legal tool to control the war powers of the executive government.

Parliamentary powers in Australia

Australia does not have a law similar to the_WPR_. The uniform practice in Australia has been for the Executive Government to commit Australian military forces to operations. No law requires the Government to consult or inform Parliament when deploying military forces. However, on most occasions the Prime Minister or the Minister for Defence has informed Parliament of Cabinets decision through a ministerial statement or tabled paper; the Governor-General has rarely issued an order orproclamation. The Executives decision to declare war or deploy forces overseas has on most occasions been taken prior to Parliament debating the issue. Historical examples of the process are documented inParliamentary involvement in declaring war and deploying military forces. The current practice is increasingly being contested.

There have been unsuccessful attempts since 1985 by the Australian Democrats and more recently by the Australian Greens to amend theDefence Act 1903to remove the exclusive power of the government to commit Australia to war. The latest attempt is theDefence Legislation Amendment (Parliamentary Approval of Overseas Service) Bill 2015.

Also in 2015, the Australians for War Powers Reform (AWPR) published a free online book,How does Australia go to war? A call for accountability and change. In September 2018, AWPR launched a public campaign,Be Sure On War: No War Without Parliament, with a petition which aims to [s]eek reform of the War Powers under which the executive government can commit troops to international conflict.

More recently, the National Labor Party Conference passed the followingresolutionon 18 December 2018:

A Shorten Labor Government will refer the issue of how Australia makes decisions to send service personnel into international armed conflict to an inquiry to be conducted by the Joint Standing Committee on Foreign Affairs, Defence and Trade. This inquiry would take submissions, hold public hearings and produce its findings during the term of the 46th parliament.

The AustralianConstitutiondoes not explicitly refer to the power of the Executive to declare war or deploy military forces. At the time the_Constitution_was written, the Royal prerogatives with respect to foreign affairs and war may have been moreproperly regardedas falling within the executive power of the British Imperial Government.From settlement to 1913, the Royal Navy provided Australias Naval defence and until 1913 Australia had no independent capacity to deploy military forces overseas.

Interpretation of the executive powersunder section 61 of the_Constitution_has changed over time. Section 61 is now considered to encompass all traditional Royal prerogatives. The power to authorise use of military force is therefore generally accepted to reside in the Governor-General who isrequired by firm conventionto act on the advice of the Executive Council.

The history of the Australian Parliaments involvement in decisions to deploy Australian forces is covered in detail in a 2010 Parliamentary Library Background Note,Parliamentary involvement in declaring war and deploying military forces. The Library has also acquired a recent academic work on the subject by Dr Cameron Moore,Crown and Sword: Executive power and the use of force by the Australian Defence Force.