What kinds of war tactics are justified for those resisting US/UK invasions?

I wrote about just war theory and the principle of non-combatant immunity in my last post. The argument was that the feudal-era justification for non-combatant immunity that comes out of just war theory does not make much sense when applied to citizens of liberal governments. It was an abstract discussion with only a passing discussion of the UK soldier killing near the end.

Apparently Glenn Greenwald wrote a piece with similar themes, although very different in substance and form. His main question is whether the killing of the soldier in the UK was terrorism. He also explains that the provided motivation for the killing was as a response to UK invasion in Muslim lands.

Terry Eagleton also has a related piece, again different in its main thrust. His main point is that explaining why someone does something is not the same thing as justifying it. So even though you can explain that they were motivated by opposition to UK invasion in Muslim lands, that does not, by itself, tell you that their action was justified.

Norman Geras also takes exception to Greenwald, although his argument is somewhat murkier. Andrew Sullivan had something to say about it too.

Most of the arguments in this discussion seem fairly irrelevant to the question that is actually being argued. From the just war theory perspective at least, we have clear guidance here, which says that non-combatants should not be targeted. I think that rule is a bit shaky given the nature of liberal governance, but we can put that argument aside for the moment. The target here was not a non-combatant. It was a soldier. From my lapsed interest in just war theory a few years ago, I at least remember that military targets are justified targets. That’s not to say you are supposed to be fine with such attacks. You are supposed to hate them because you want to beat your enemy and whatnot. But it is never held to be an unjust tactic.

In any case, I think this whole discussion is better served, if instead of focusing on this incident, the relevant writers answered this question: what kinds of war tactics are justified in the context of US/UK incursion into Muslim lands?

We know that the US and UK are on the ground in military operations in Afghanistan. The US is bombing Pakistan regularly. These are acts of war and are explicitly described as such (“war on terror”). Even if you think those acts of war are justified acts, the just war rules still allow for resistance. So we don’t even need to get into the subject of whether the US/UK are justified in their military operations: the rules governing the tactics available to those opposing those military operations are no different.

So what kind of tactics would be justified? What sort of things could someone do to violently resist US/UK incursion and it be considered a justified act of warfare? Right now, the answer for most appears to be: nothing. Even fighting active combat troops on the ground in these countries is regarded as unjustified terrorism in most of the reports I read. Is that really the position though? Is it really the case that those subject to invasion by another country are not entitled to do anything justifiably?

Until participants in the debate start answering the question of what resisters to UK/US invasions are allowed to do justifiably, these act-by-act discussions are so unstructured that they border on pointless. For worthwhile debate, we need commitments to a positive theory of what war tactics are justified in this context, not ad-hoc negations of whatever the latest attack is.

Update: From the action on twitter, it is clear that a second question necessary to ask is: who is permitted to violent resist US/UK invasion? Is it only those in the affected countries, only those directly affected, anyone who opposes it? The usual nation-state distinction will prove, I think, unhelpful insofar as the war itself is not advertised as targeted against particular nation-states, not anymore at least (“global war on terror”). h/t interfluidity