What is a military duty?

Today the United States Court of Appeals for the Armed Forces decided United States v. Blanks. Affirming a decision of the U.S. Air Force Court of Criminal Appeals, the court, in a scholarly opinion by Judge Kevin A. Ohlson invoked stare decisis for the proposition that negligent dereliction of duty is an offense under the Uniform Code of Military Justice.

So far so good. But the offense at issue was the accused's negligent dereliction of duty in failing to provide adequate financial support to his dependent spouse. Dereliction of duty requires, among other things, some duty. In military law, I would argue, the duty ought to be of a military character. The Manual for Courts-Martial explains "duty" as follows:

A duty may be imposed by treaty, statute, regulation, lawful order, standard operating procedure, or custom of the service.

What was the source of the duty this enlisted accused failed to perform through negligent dereliction? Principle No. 8 of the Draft Principles Governing the Administration of Justice Through Military Tribunals provides that "[t]he jurisdiction of military courts should be limited to offences of a strictly military nature committed by military personnel." But simply labeling a GI's failure to provide spousal support dereliction doesn't make it a military offense. In United States v. Hayes, 71 M.J. 112 (C.A.A.F. 2011), another unanimous decision, the court observed (in note 2):

The various iterations of the MCM beginning in 1951 and culminating in the current 2008 version list examples of conduct to illustrate the limits of Article 92(3), UCMJ. All of the examples listed constitute military-specific duties. See, e.g., MCM para. 171c (1951 ed.); MCM para. 171c (1969 ed.); MCM pt. IV, para. 16.c.(3)(d). A review of our jurisprudence uncovered no example of this Court affirming a conviction for dereliction of duty imposed by state law alone. See United States v. Shavrnoch, 49 M.J. 334, 339 (C.A.A.F. 1998) (accused guilty of dereliction of duty for under-age drinking based on an Air Force regulation); United States v. Bivins, 49 M.J. 328, 332 (C.A.A.F. 1998).

Bottom line: Color me skeptical. Perhaps there was evidence of a custom of the service, but even so, the conduct at issue in the disputed finding of guilt that was examined in Blanks should have been adjudicated, if anywhere, in a state domestic relations court, not a criminal court, and certainly not a court-martial.