Don't recall Chris said Marxism *invariably* defends right to NSD, but whether "it" (whatever that means) does or not is less important than whether the left should support it, and if so, when.
The Civil War also raises a question for the implacable opponents of NATO. NATO policy is often criticized because a) its motives are not humanitarian, b) the cost of intervention to civilians would be high; c) the leadership of the group being defended (the KLA or the Albanian govt) is problematic; d) the "bad guys" are supporting NATO. All these things were true of the Union in the Civil War. Union motives were principally maintaining the Union, and clearly the interests of Northern capital vis-a-vis Southern economic interests were significant; anti-slavery was a justification for intervention, but not the prime motive. The toll on the working class on both sides was horrendous, and continued in the South for decades after. Reconstruction governments, while allowing the franchise to blacks, provided much grist for criticism, especially to a purist revolutionary standpoint. And the bad guys -- British imperialism -- sided with the South, albeit in limited ways. The arguments against NATO could be applied to the case for the Union, hence they fail the Appomatox Test and reveal their inherent illogic and unMarxism.
mbs