Last week’s awful tragedy at Los Angeles International Airport, which by all accounts involved a lone and troubled individual, was notable for the commendable calmness surrounding it. There were no calls for military detention, no cries of “act of war,” no demands that the President intervene to prevent the accused, Paul Ciancia, from “lawyering up” such as were heard in the aftermath of the Boston Marathon bombing. But the act itself is difficult to distinguish from what, in other cases, is described as terrorism that supposedly exceeds the competence or jurisdiction of civilian authorities. It was politically motivated: Ciancia’s writings were laced with anti-government sentiment. It was an explicit attack on government agents in the performance of their duties. It terrorized civilians.

A gut check, of course, tells us the difference: This individual may have been mentally ill. There is no evidence of connection to foreign groups. Yet these are things we know after investigation. By outward signs, consistency ought to have impelled the same people who wanted Dzhokhar Tsarnaev militarily detained immediately after the Boston Marathon to call for the same treatment after the LAX tragedy. We do not know, after all, that the same qualities—mental illness, home-grown terror rather than foreign instigation—do not apply to Tsarnaev; certainly we did not know it in the instantaneous aftermath of the bombing when calls for enemy-combatant status were being heard.

Regardless of what they may tell us, gut checks are not legal standards, and acts of war and acts of derangement—if the LAX shooting turns out to have been the latter—are exceptionally difficult to distinguish from one another based simply on the characteristics of the deed, especially before the first clue has been uncovered. The fact that the Tsarnaev case is, upwards of six months on, being handled in civilian court with evident competence raises serious questions about the excited demands for military detention that surrounded the Marathon bombing. (Liz Cheney’s breathless post-Marathon tweet: “Obama admin will treat terrorist as ‘criminal’ not enemy combatant. Will Obama let him lawyer up?” What precisely, based on what we knew at the time that tweet was posted, makes Cianci different?)

The cases illustrate the dangers to liberty of creeping militarism in the handling of criminal affairs. Angelo M. Codevilla has already alerted us to multiple instances of the militarization of police. (In my sleepy New England town, an open house for children at the combined police/fire station recently featured a proud display of the AR-15s officers now carry—for purposes unknown, unless to enforce proper autumnal leaf collection, but it would be shocking if Congressional homeland security grants were not somewhere involved.)

Given the inevitably blurred line between terrorism and crime, the reflexive use of military systems to respond to the former almost inevitably means they will creep toward the latter. What Madison called the inherently encroaching nature of power strongly suggests the definition of terrorism will similarly expand. (“Terrorism” is already an etymological weapon in political debates; see dueling examples here and here.) Are drug gangs terrorists too? School shooters? If not, how can we tell the difference?

There is danger to liberty in the confusion, and a potential safeguard for it in the fact that no one seems to see a need for military justice in the LAX tragedy. The question is what outward significations distinguish it from cases in which such treatment is demanded. Perhaps the lesson that emerges from these cases is that the normal Constitutional order is both strong and flexible enough to handle them after all—and that all wars must have both boundaries and what those wielding power seem stubbornly to resist in the case of this one: ends.