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Congress’s Role in Military Conflict: The Growing Gap Between Constitutional Principle and Practice

There are glimmers of congressional interest in taking at least some power back from the president.

Published: January 15, 2020

This piece is adap­ted from remarks presen­ted at a symposium sponsored by the Legis­lat­ive Branch Capa­city Work­ing Group (a joint project of R Street Insti­tute and New Amer­ica) held at the Capitol Visitor Center in Wash­ing­ton on Novem­ber 12, 2019.

When it comes to Congress’s role in initi­at­ing milit­ary conflict, there’s a grow­ing gap between what’s specified in the Consti­tu­tion and what we’re seeing in prac­tice. 

As we all know, the Consti­tu­tion gives Congress the power to declare war. The founders assigned this role to Congress because they wanted to make it hard to get into wars. As James Madison wrote, “The consti­tu­tion supposes, what the History of all Govern­ments demon­strates, that the Exec­ut­ive is the branch of power most inter­ested in war, and most prone to it. It has accord­ingly with stud­ied care, vested the ques­tion of war in the Legis­lature.”

An earlier draft had given Congress the power to “make war.” The rati­fic­a­tion history clearly indic­ates two reas­ons why “make war” was replaced with “declare war.” First, the change was meant to preserve the pres­id­ent’s abil­ity to “repel sudden attacks” without advance congres­sional author­iz­a­tion. Second, it would ensure that Congress did not micro­man­age the actual conduct of the war, which was entrus­ted to the pres­id­ent as Commander in Chief of the armed forces.

Formal declar­a­tions of war proved to be quite rare. But up until the mid-20th century, milit­ary engage­ments gener­ally were conduc­ted pursu­ant to stat­utory author­iz­a­tion short of a formal declar­a­tion, a prac­tice the Supreme Court upheld in 1800. That was the norm until Pres­id­ent Truman sent Amer­ican forces into Korea.

Since that time, we’ve seen an increas­ing pattern of pres­id­ents initi­at­ing milit­ary action over­seas without congres­sional author­iz­a­tion. Modern examples (post-Viet­nam) include: 

  • Pres­id­ent Reagan’s strikes against Libya after the Beirut bomb­ing
  • Pres­id­ent George H.W. Bush’s inter­ven­tion in Panama and intro­duc­tion of U.S. troops into Somalia
  • Multiple milit­ary deploy­ments by Pres­id­ent Bill Clin­ton, includ­ing actions in Bosnia, Haiti, Kosovo, Sudan, and Afgh­anistan
  • Pres­id­ent George W. Bush’s inter­ven­tion in Haiti
  • Pres­id­ent Obama’s airstrikes in Libya and in Yemen
  • Pres­id­ent Trump’s airstrikes in Syria

 To a shock­ing degree, the justi­fic­a­tion for this pattern has rested on pure boot­strap­ping. In OLC opin­ion after OLC opin­ion, the exec­ut­ive branch has argued that it has the consti­tu­tional author­ity to initi­ate armed conflict without congres­sional approval because it has repeatedly done so, and because Congress has acqui­esced. As a result, what was initially under­stood as a narrow Article II author­ity to “repel sudden attacks” has been rechar­ac­ter­ized as a sweep­ing author­ity to engage in milit­ary oper­a­tions to defend “import­ant national interests,” as long as those oper­a­tions fall short of full-fledged “war.”

A theor­et­ical constraint on this author­ity is the War Powers Resol­u­tion of 1973, or WPR. Under the WPR, the pres­id­ent must report to Congress within 48 hours of intro­du­cing armed forces into hostil­it­ies or situ­ations where hostil­it­ies might be immin­ent. Within 60 days of the dead­line for report­ing, or 90 days if exten­ded by the pres­id­ent, the pres­id­ent must end the milit­ary action unless Congress has author­ized it. Congress also can require the pres­id­ent to with­draw armed forces by passing a concur­rent resol­u­tion, or a so-called legis­lat­ive veto, which takes effect without the pres­id­ent’s signa­ture. 

The WPR hasn’t worked, for several reas­ons. First, instead of read­ing the 60-to-90-day limit­a­tion as a back­stop to enforce consti­tu­tional limit­a­tions, pres­id­ents have read it as acknow­ledging the pres­id­ent’s author­ity to conduct milit­ary oper­a­tions without congres­sional approval for a period of 60 to 90 days.

Second, pres­id­ents have routinely evaded the report­ing require­ment by inter­pret­ing the term “hostil­it­ies” to exclude most of the tech­niques and prac­tices that char­ac­ter­ize modern warfare. Once again, Congress has almost completely acqui­esced, making no effort either to author­ize or to prohibit milit­ary actions begun by pres­id­ents without the required report­ing. 

Finally, in 1983, the Supreme Court held that a legis­lat­ive veto provi­sion in a differ­ent law was uncon­sti­tu­tional. While it’s not a certainty that the WPR’s concur­rent resol­u­tion provi­sion would meet the same fate, it’s quite possible that Congress would need to pass a joint resol­u­tion instead, which would effect­ively require a veto-proof super­ma­jor­ity. 

Up to now, I’ve been talk­ing about the prob­lem of pres­id­en­tial war-making without advance congres­sional author­iz­a­tion. But another trend in modern history is pres­id­ents exceed­ing the scope of congres­sional author­iz­a­tions when Congress does provide them. A living example is the 2001 Author­iz­a­tion for Use of Milit­ary Force.

The 2001 AUMF author­ized the use of milit­ary force against “those nations, organ­iz­a­tions, or persons who [the pres­id­ent] determ­ines planned, author­ized, commit­ted, or aided the terror­ist attacks that occurred on Septem­ber 11, 2001, or harbored such organ­iz­a­tions or persons.” Eight­een years later, this law has been invoked 37 times to support conflicts occur­ring in 14 differ­ent coun­tries, against organ­iz­a­tions that did not even exist on 9/11. Three success­ive admin­is­tra­tions have accom­plished this feat by inter­pret­ing the 2001 AUMF to apply, not only to the enemies specified, but to any “asso­ci­ated forces,” a term that the exec­ut­ive branch has stretched beyond any common­sense mean­ing.

The obvi­ous solu­tion for such over­reach is for Congress to repeal or clarify the author­iz­a­tion or refuse to fund the extraneous milit­ary activ­it­ies. Instead, a bill intro­duced by Senat­ors Bob Corker and Tim Kaine in 2018 would have given congres­sional bless­ing to pres­id­en­tial war-making by adopt­ing the exec­ut­ive branch’s defin­i­tion of “asso­ci­ated forces” and author­iz­ing the pres­id­ent to determ­ine who qual­i­fies. In other words, the bill would have provided author­ity to the pres­id­ent to use milit­ary force against enemies of his choos­ing. That would deleg­ate away the most cent­ral aspect of Congress’s war-making author­ity: the desig­na­tion of the enemy. 

Why does any of this matter? Recall that a main purpose of giving Congress the power to declare war was to keep us out of wars. We have now been at war for 18 years, the longest in our coun­try’s history. Today, soldiers are being deployed to fight in a war that star­ted before they were born. We have spent over 6 tril­lion dollars on the conflict. More than 6,000 Amer­ican soldiers have lost their lives, with nearly 50,000 injured. By conser­vat­ive estim­ates, 30,000 civil­ians have been killed in Afgh­anistan. This is exactly what the founders sought to avoid. 

There are signs that Congress is inter­ested in taking back some of the power it has given away in the area of war powers and in related areas of foreign rela­tions and national secur­ity. In April, Congress voted to end U.S. milit­ary activ­it­ies in Yemen. In July, Congress passed three resol­u­tions to block arms sales to Saudi Arabia and the United Arab Emir­ates. In March and again in Septem­ber, Congress voted to termin­ate the national emer­gency Pres­id­ent Trump declared to divert fund­ing to his border wall.

Thus far, these efforts have failed because Congress cannot muster the neces­sary super­ma­jor­ity to over­ride the pres­id­ent’s veto. The lesson is clear: once Congress gives away its power, it is exceed­ingly diffi­cult to take it back.