Any attempt to authorize domestic military deployments by designating fentanyl a weapon of mass destruction rests on absurd legal theories.
On Dec. 15, 2025, President Trump signed an executive order designating “illicit fentanyl and its core precursor chemicals as weapons of mass destruction (WMD).” Thus far, much of the commentary on the executive order concerns how it may be used to buttress legal arguments for unlawful military strikes in the Caribbean and Pacific. But it also has important implications for future domestic military deployments, just as these deployments have come to an end in Los Angeles, Chicago, and Portland after the Supreme Court’s order in Trump v. Illinois.
As David Del Terzo and James Dunne have helpfully laid out, the executive order directs the defense secretary and attorney general to determine whether the Justice Department requires Department of Defense resources under 10 U.S.C. § 282 to counter the threat posed by fentanyl. Provided a number of criteria are met, § 282 authorizes the Pentagon to assist the Justice Department’s enforcement of three criminal statutes concerning weapons of mass destruction. Crucially, § 282 is also a statutory exception to the Posse Comitatus Act, which generally prohibits the use of the military for domestic law enforcement functions. But under any reasonable interpretation of § 282, it is simply inapplicable to the threat currently posed by fentanyl in the United States.
Section 282 contains important textual limitations. Military support must be related to the Justice Department’s enforcement of criminal laws regarding WMDs (18 U.S.C. § 2332a), as well as biological (18 U.S.C. § 175) and chemical weapons (18 U.S.C. § 229). It must also be consistent with regulations jointly prescribed by the Pentagon and the Justice Department. These regulations can authorize arrest or direct participation in searches and seizures only if necessary for the immediate protection of human life. Importantly, civilian law enforcement officials must also be incapable of taking action. On nearly all of these points, any attempt to use § 282 to authorize military support, including a military deployment, should fail.
Let’s start at the top. What is an “emergency situation involving a weapon of mass destruction?” Well, it must involve a WMD. What’s that? Del Terzo and Dunne have noted that § 282 doesn’t have a definition itself, but the statute that enacted § 282 does. The statute defines a WMD as “any weapon or device that is intended, or has the capability, to cause death or serious bodily injury to a significant number of people through the release, dissemination, or impact of—(A) toxic or poisonous chemicals or their precursors; (B) a disease organism; or (C) radiation or radioactivity.”
Fentanyl is not a pathogen or any form of radiation. It’s a synthetic opioid drug, as characterized by the Drug Enforcement Administration (DEA). Fentanyl is plausibly a toxin or a poisonous chemical (numerous derivatives are listed as Schedule I drugs, for which there is no medical use). But it also is not, on its own, a “device” or a “weapon” in the ordinary sense of either word. An example that would apply under the statute is some kind of mechanism that releases fentanyl to kill or injure a “significant number of people” at a single time. The only instance of fentanyl being used in such a manner appears to have been in 2002, when Russian authorities, during a hostage crisis, weaponized the opioid into gas form, killing 130 people. This is, of course, quite distant from how fentanyl is typically delivered in the United States today—either consumed directly as a powder or pill or intravenously by needle. Neither the bags nor the needles used by individuals are plausibly “devices” or “weapons,” and they certainly don’t release, disseminate, or impact any large number of people at once.
Even if we assume for a moment that fentanyl is such a device or weapon, the current threat posed by fentanyl cannot plausibly be an “emergency situation,” which must meet two criteria under § 282. First, an emergency situation must pose “a serious threat to the interests of the United States.” Let’s say that fentanyl is a serious threat to U.S. interests (in any event, courts are likely to defer to the administration on this determination). The second criterion, then, requires that three factual conditions be met:
- “Civilian expertise and capabilities” must not be “readily available to provide the required assistance to counter the threat immediately posed by the weapon involved,”
- “Special capabilities and expertise” of the Department of Defense must be “necessary and critical to counter the threat posed by the weapon involved, and
- Enforcement of § 175, 229, or 2332a of Title 18 would be seriously impaired without the Department of Defense’s support.
This second set of criteria presents a number of interrelated problems. First is the question of expertise. What about countering the weapon is outside civilian expertise or unique to the Department of Defense? Are civilian law enforcement agents incapable of stopping someone from reaching into a bag or operating a needle? If we stretch the definition of a weapon or device, are they unable to stop someone from transporting or delivering a package of fentanyl? A shipping container? How is the military needed for any of this? A second issue has to do with timing. Assistance must be necessary in countering a threat that’s posed immediately by a WMD. The assistance can’t be in response to the general threat posed by fentanyl. For example, that once trafficked into the United States, fentanyl will eventually kill or injure some unknown number of individuals doesn’t hold up under § 282. The threat to life or health must be imminent. Again, the hypotheticals are absurd. Can DEA agents not stop someone from consuming fentanyl? Must a battalion be at their side to help restrain someone from taking drugs?
Moving on, support by the Department of Defense under § 282 must relate to the enforcement of three criminal statutes, but none of them plausibly relate to the current threat posed by fentanyl. 18 U.S.C. § 175 concerns biological weapons. Fentanyl can’t be classified as any of the biological agents listed by the statute (e.g., a microorganism, infectious substance, component of a microorganism or infectious substance, or toxic material or product of a plant, animal, or microorganism). 18 U.S.C. § 2332a prohibits using WMDs in the U.S. and against U.S. citizens abroad. Under this statute, the definition of “WMD” is broader than what we see for § 282 itself, but not in a way that’s helpful to the administration. As Del Terzo and Dunne have noted, fentanyl is not a “destructive device” as defined by 18 U.S.C. § 921, which § 2332a incorporates by reference. It also doesn’t match any of the other definitions on which § 2332a relies.
Finally, 18 U.S.C. § 229 seemingly provides the best ground on which the administration might proceed. It prohibits the transfer, retention, ownership, use, or threat of use of any chemical weapon. Its substatute, 18 U.S.C. § 229F, provides that a chemical weapon is “a toxic chemical and its precursors.” In a move that might seem to help the administration, there is no requirement that a “weapon” or “device” be used.
The Supreme Court, however, has curtailed adventurous uses of § 229 significantly. In Bond v. United States, federal prosecutors charged Carol Bond under § 229 for spreading toxic chemicals on her friend’s car door, mailbox, and doorknob. Chief Justice John Roberts, however, found that the statute—which implements the Chemical Weapons Convention—did not authorize treating “a local assault with a chemical irritant as the deployment of a chemical weapon.” Crucially, the Bond Court construed “chemical weapon” under § 229 narrowly, as those chemicals “associate[d] with instruments of chemical warfare.” And it stipulated that the term “chemical weapon” incorporated plain language definitions of “weapon,” namely, that they are an “instrument of attack or defense in combat, as a gun, missile, or sword.” Perhaps most importantly, the Court determined that context mattered. Bond’s chemicals could have been a chemical weapon if used “to poison a city’s water supply,” but not in an “act of revenge,” like Bond’s attack on her friend.
To be sure, fentanyl causes far greater harm than Bond’s irritating chemicals. Yet it again strains credulity to say that drug trafficking is similar to the chemical warfare that the Supreme Court read § 229 as prohibiting. Unsurprisingly, in the years since Bond was decided, I can find no case in which § 229 has been used to prosecute someone for trafficking fentanyl or any other controlled substance.
The remaining hurdles are procedural or reiterate issues already discussed. Section 282 requires that the Department of Defense and Justice Department jointly promulgate regulations governing support under § 282. I can find no evidence in the Department of Defense’s regulations or the Code of Federal Regulations that these regulations exist. Further, any § 282 deployment involving an arrest or direct participation in a search or seizure could only be done when necessary for the immediate protection of human life and when civilian law enforcement officials are incapable of taking action. As discussed above, it is incredibly difficult, if not impossible, to imagine what it would mean to use the military to immediately protect someone from consuming fentanyl, and in what plausible circumstances a civilian law enforcement officer would be incapable of intervening, not just unavailable, to stop someone from using it.
Fentanyl, scourge though it is, is not a WMD. This is true as a matter of common sense and for purposes of Section 282.
– Chris Mirasola is an Assistant Professor of Law at the University of Houston Law Center. Previously, he was a Climenko Fellow and lecturer on law at Harvard Law School and an attorney-advisor at the Department of Defense Office of General Counsel. Published courtesy of Lawfare.
