Beginning with President Truman's decision to go to war against North Korea without congressional approval, U.S. presidents of both parties have unilaterally ordered the use of military force. As George Washington correctly recognized, the Constitution "vests the power of declaring war with Congress; therefore no offensive expedition of importance can be authorized until they [Congress] have deliberated upon the subject, and authorized such a measure." Washington had it right — the drafters of the Constitution only intended for presidents to act unilaterally in an emergency, when there was no time to consult Congress.
ISIS is such a hideous group that this particular action may not bother us, and may not bother members of Congress. Most Americans, and most legislators, may not see the need for insisting that Congress play a role in deciding whether it makes sense to act against ISIS. The precedent, however, should be reason for concern. Even if we think it makes sense to go to war with ISIS, and even if we trust President Obama (or a President Marco RubioMarco RubioRepublicans giving Univision the cold shoulder: report Week ahead: Senate panel to vote on Trump's Labor pick Senators introduce new Iran sanctions MORE or Hillary ClintonHillary Rodham ClintonWith GOP’s healthcare bill on ice, Dems go on offense Trump tweets: 'Trump Russia story is a hoax' Path to 60 narrows for Trump pick MORE) to make this decision alone, it's worth thinking through what this could mean.
After Super Tuesday, Donald TrumpDonald TrumpWith GOP’s healthcare bill on ice, Dems go on offense Trump to undo Obama's climate change agenda Kushner met Russian bank executives: report MORE is riding a powerful political wave. He seems poised to win the Republican nomination for president. Let's imagine he does, in fact, win that nomination. Let's further imagine that he wins the general election and becomes president. A President Trump would be poised to rely on the precedent, based on past practice, that presidents can unilaterally decide when to order the use of military force. The Obama administration has suggested that there may be some limits to that precedent — that presidents may only order the use of military force when it is in the national interest to do so, and when such actions do not rise to the level of war (under the Constitution) or hostilities (under the War Powers Resolution). But even assuming that Trump decided to recognize such principles, those apparent limits leave a great deal of room for presidents to act. Devastating military force can be deployed without (in the Obama administration's view) rising to the level of war or hostilities. "National interest" is a highly subjective standard. The Obama Department of Justice noted that it could include "preserving regional stability." Trump might decide regional stability is threatened by a flow (whether real or imagined) of immigrants from Mexico. He might conclude it is essential to regional stability that he achieve his chimerical goal of making Mexico pay for a border wall, and he might determine military force is necessary to force Mexico's hand. This reasoning may well seem ludicrous and unsustainable. But, unless Congress were to demonstrate a rare ability to play its constitutional role when it comes to war power, Trump would be free to act.
Trump could also conclude that his unilateral power extends beyond decisions to use military force. Executive branch lawyers in the George W. Bush administration concluded that the president, as commander in chief, has inherent authority to make decisions about which interrogation methods to use with prisoners. This inherent authority, lawyers concluded, cannot be restrained even by criminal law. In other words, the president can order interrogation methods (like waterboarding) that violate U.S. criminal law against torture. The Obama administration has not endorsed this radical legal theory, but it also declined to punish anyone for authorizing torture. Trump might reasonably conclude that he and his administration could authorize waterboarding, or other methods of torture, with impunity.
Our Constitution was built on the premise that no person, not even the president, can set aside the law and no one person, not even the president, can take the country to war. The dangerous implications of recent precedent, especially since 9/11, that rejects these constitutional standards should be crystal clear to us when we contemplate the possibility of a Trump presidency.
Edelson is an assistant professor of government in American University’s School of Public Affairs. His book, "Power Without Constraint: The Post 9/11 Presidency and National Security," will be published in spring 2016 by the University of Wisconsin Press.