The international law governing when states may target to kill or preventively detain nonstate actors is in disarray. This Article puts much of the blame on the method that international law uses to answer that question. The method establishes different standards in four regulatory domains: (1) law enforcement, (2) emergency, (3) armed conflict for civilians, and (4) armed conflict for combatants. Because the legal standards vary, so too may substantive outcomes; decisionmakers must select the correct domain before determining whether targeting or detention is lawful. This Article argues that the "domain method" is practically unworkable and theoretically dubious. Practically, the method breeds uncertainty and subverts the discursive process by which international law adapts to new circumstances and holds decisionmakers accountable. Theoretically, it presupposes that the domain choice, rather than shared substantive considerations embedded in the domains, drives legal outcomes. This Article argues, to the contrary, that all targeting and detention law is and ought to be rooted in a common set of core principles. Decisionmakers should look to those principles to assess when states may target or detain nonstate actors. Doing so would address the practical problems of the domain method. It would narrow the uncertainty about when targeting and detention are lawful, lead to a more coherent legal discourse, and equip decisionmakers to develop the law and hold one another accountable.
When courts analyze whether a defendant's prior conviction qualifies as a "violent felony" under the Armed Career Criminal Act's "residual clause," they use a "categorical approach," looking only to the statutory language of the prior offense, rather than the facts disclosed by the record of conviction. But when a defendant is convicted under a "divisible" statute, which encompasses a broader range of conduct, only some of which would qualify as a predicate offense, courts may employ the "modified categorical approach." This approach allows courts to view additional documents to determine whether the jury convicted the defendant of the Armed Career Criminal Act-qualifying part of the statute. This Note identifies a split among the circuit courts regarding when a statute is divisible. Under the "formal method," a statute is divisible only when its text specifies qualifying and nonqualifying categories of conduct. By contrast, courts that employ the "functional method" divide a statute if, regardless of the statute's text, it is possible to violate the statute in a way that amounts to a "violent felony" and in a way that does not amount to a "violent felony." This Note contends that the text-based "formal method" is more consistent with the Supreme Court's Armed Career Criminal Act jurisprudence, the Sixth Amendment, and the rule of lenity. Finally, it argues that the "formal method" gives Congress the strongest incentive to revise the vague and confusing Armed Career Criminal Act.