Combatants or non-combatants is a MAJOR distinction. Additionally, the main point is that using these tactics is a way to AVOID killing thousands of soldiers whereas terrorism is used because you CAN'T kill thousands of people with the means at your disposal (but would still like to create a large effect).

If you read the paper I linked to, this tactic was created in response to terrorism (ie, no nation in the world can go head-to-head in a tank battle with the US). The link is quite interesting because they do make the point that the decision of whether or not this tactic "should" be used or would be accepted by the public is best left to a broader examination by an outside source.