This general idea, Buchanan suggests, applies to both JWN and PSDN in much the same way.
However, Buchanan clearly suggests, though he does not explicitly dwell on the point, that there is an important asymmetry between JWN and PSDN (as well as other plausible substantive moral justifications for aggressive war, like the forcible democratization rationale).
Contrast this observation about the force of PSDN with what happens to JWN when the latter is superseded by a proper institutional framework.
PSDN, therefore, does not conflict with the principle that we may not aggress against the innocent.
Buchanan is committed to the view, to conclude, that JWN is dependent on institutional context in a much stronger sense than PSDN (or other convincing moral justifications for the use of aggressive force).
It follows that the standoff between JWN and PSDN, in Buchanan's view, is not a conflict between different moral values.
Rather, we will at least have to be able to appeal to PSDN, if we are to have any chance of survival in that state (Hobbes 1991: 91-111).