Swedish Foreign Minister Margot Wallstrom provoked outrage in Israel when she alleged that the nation was engaging in "extrajudicial executions" when police forces killed terrorists engaged in stabbing attacks in civilian areas. Israel has responded by declaring that Wallstrom is no longer welcome in the country.
The bases for critiquing Wallstrom are legion, including the usual charges of hypocrisy (police officers in Europe -- including Sweden and France -- have killed armed assailants before, without any fretting by Wallstrom about the deaths constituting "executions"). Harvard Law Professor Noah Feldman also observes that Wallstrom seems to badly misunderstand the relevant international law principles she purports to be defending. Most notably, Feldman observes that even if police use of lethal force in stopping an armed attacker presents an international law question in the first place (far from clear), the international law language she appeals to is that governing armed conflict, not criminal conduct. Questions of "proportionality" and "distinction" refer to the legality of military strikes which will result in civilian casualties in pursuit of a bona fide military objective. Civilian and military targets must be distinguished, and civilian casualties must be proportionate to the military objective pursued. These considerations are simply inapposite where the police are seeking to stop an identified criminal in a civilian context.
There's another point worth making here that Feldman does not raise. Obviously, some defenders of Palestinian attacks on Israel would argue that these are military, not criminal actions. It's possible that this is the view that Wallstrom is seeking to channel: the stabbing attacks conducted by Palestinians against Israelis are part of an ongoing military conflict between Israel and Palestine, and so therefore Israel's response should be thought of in terms of the laws of war.
Obviously, the goal of this framing is to elevate the stabbing attacks beyond that of unsavory criminality. The stabbers are not mere criminals, but soldiers, entitled to all the respect that position entails. Now there are all sorts of reasons why characterizing stabbing attacks as military operations is problematic, and another lengthy list of reasons why if they are "military" they're also war crimes. But putting that aside, Wallstrom and other advocates of "militarizing" Palestinian stabbing attacks overlook one essential characteristic of the laws of war relevant to this conversation:
Soldiers can be killed.
This is a bedrock feature of the law of armed conflict: it is obviously not illegal (in of itself) to kill a soldier on the battlefield. They can be killed immediately, without warning, and without opportunity to surrender. And one can kill as many soldiers as one wants. There is no "proportionality" requirement with respect to combatants. Nor is there a requirement that they be given judicial process. A combatant who does legitimately surrender is entitled to have that surrender accepted, and upon capture is entitled to various protections as a POW. But there is no obligation to try and take enemy soldiers alive. If they're there and they're active, they can be killed -- even if they aren't an immediate threat to kill someone.
In this way, one might say, it's sometimes better to be a criminal than a soldier. Criminals are entitled to judicial process; that's the process through which they are punished. Killing a criminal on the street is only justified if there is an objective, imminent threat to someone's safety (the officers or surrounding civilians). None of that is necessary to kill a soldier. This oddity exists because, odd as this might sound, killing a soldier is not taken to be punitive. We don't kill soldiers on the battlefield as punishment for them breaking a law (being a soldier does not, in itself, break a law). We kills soldiers on the battlefield because that's what war is. And so by the same token, a captured soldier cannot be punished simply by virtue of their status as a soldier. Detention in a POW camp is also non-punitive; it is lawful as a means of incapacitating an enemy force. To punish an enemy soldier -- e.g., to hang him -- you need to charge him with a crime (such as a war crime). But judicial process is not something that exists on the battlefield itself.
For my part, I think it is evident that the Palestinian knife attackers are not soldiers, but ordinary criminals. And so that does mean that they are subject to ordinary rules of policing, which means they cannot be killed unless they pose an imminent safety threat. But if their defenders want to cloak them in the garb of the soldier, they need to accept the consequences of the label. Soldiers can be killed in war. That's what war is. And if it's a war Palestine wants, Israel is not under any obligation to lose it.