Why Is Israel’s Blockade of Gaza Legal? (Updated)

I know that will sound like a provocative question, but it’s not meant to be.  According to the Jerusalem Post, Israel justifies its interdiction of the “Freedom Flotilla” by reference to Article 67(a) of the San Remo Manual on International Law Applicable to Armed Conflict at Sea, which permits the attack of neutral merchant vessels that “are believed on reasonable grounds to be carrying contraband or breaching a blockade, and after prior warning they intentionally and clearly refuse to stop, or intentionally and clearly resist visit, search or capture.”  The interdiction thus depends on the legality of the blockade of Gaza — and I am genuinely confused as to why that blockade is legal.  The Jerusalem Post says the Israeli government is arguing that “Israel was in a state of armed conflict with Gaza and therefore entitled by international law to blockade Gaza.”  But that defense ignores a critical question: what kind of armed conflict?

If the conflict between Israel and Hamas is an international armed conflict (IAC), there is no question that Israel has the right to blockade Gaza.  (Which is not to say that the manner in which Israel is blockading Gaza is legal.  That’s a different question.)  The 1909 Declaration Concerning the Laws of Naval War (the London Declaration), the first international instrument to acknowledge the legality of blockades, specifically recognized the right of belligerents to blockade their enemy during time of war.  Article 97 of the San Remo Manual does likewise.  And there is certainly no shortage of state practice supporting the legitimacy of blockades during IAC (the US blockade of Cuba, for example).

But what justifies a blockade in non-international armed conflict (NIAC)?  The London Declaration does not justify such a blockade, because it only applies to “war”– war being understood at the time as armed conflict between two states.  Does the San Remo Manual justify it?  The Manual is not a picture of clarity concerning when its rules apply, but it does not seem to contemplate non-international sea conflicts.  Article 1 speaks of “the parties to an armed conflict at sea,”  which does not seem to include NIAC, unless perhaps a rebel group has a navy.  (Do any?)  Article 2 parallels the Martens Clause in the 1907 Hague Convention (IV) Respecting the Laws and Customs of War on Land, which only applies to IAC.  Article 3 acknowledges the right of self-defense under Article 51 of the UN Charter, but — as Marko Milanovic has pointed out — that right is an exception to the prohibition on the use of force in Article 2(4), which only operates between states.  And numerous articles in the Manual refer specifically to “belligerent States” (see, for example, 10, 20, 34).

There also appears to be little, if any, state practice to support the idea that a blockade is legally permissible in NIAC.   According to the Jerusalem Post, the Israeli government is defending the blockade by citing Yoram Dinstein’s statement that “there are several instances of contemporary (post-UN Charter of the Law of the Seas) practices of blockades, e.g. in the Vietnam and in the Gulf War.”  But those were all blockades in IAC.  I can’t think of any blockades in NIAC other than Israel’s blockade of Gaza — though readers should feel free, of course, to correct me.

The seeming absence of support for blockades in NIAC is obviously important, because it is difficult to argue that Israel is involved in an IAC with Hamas.  First, it is obviously not in a traditional IAC, because Gaza is not a state.  Second, not even Israel claims that the conflict has been internationalized by the involvement of another state.  And third, although the Israeli Supreme Court held — controversially — in the Targeted Killings case that armed conflict between an occupying power and a rebel group is international, Israel’s official position is that it not currently occupying Gaza.

Israel’s defense of the blockade thus appears to create a serious dilemma for it.  Insofar as Israel insists that it is not currently occupying Gaza, it cannot plausibly claim that it is involved in an IAC with Hamas.  And if it is not currently involved in an IAC with Hamas, it is difficult to see how it can legally justify the blockade of Gaza.  Its blockade of Gaza, therefore, seems to depend on its willingness to concede that it is occupying Gaza and is thus in an IAC with Hamas.  But Israel does not want to do that, because it would then be bound by the very restrictive rules of belligerent occupation in the Fourth Geneva Convention.  (For a discussion of the difference between the humanitarian obligations imposed by belligerent occupation and by blockades, see Dapo Akande’s post at EJIL: Talk! here.)

There is, however, another possibility: that Israel’s blockade of Gaza is not a “belligerent blockade” at all, but is instead something akin to a “pacific blockade,” defined by the Dictionary of International Law as “a form of coercive measure short of war, whereby a state (or group of states) bars access to the coast of a state or part of it in order to prevent entry and exit of ships of the state under blockade.”  I say “akin to” a pacific blockade, because — as the definition indicates — such blockades assume that the blockaded entity is a state, not a non-state actor.  Even if Israel’s blockade of Gaza would analogically qualify as a pacific blockade, however, it would still be of questionable legality: pacific blockades are only legal with the approval of the Security Council, according to the Dictionary of International Law, and the Security Council has never approved the blockade of Gaza.

It seems to me, in short, that it is difficult to argue Israel has the legal right to blockade Gaza.  But let me be clear — I am not certain that I am correct. I am not an expert regarding the law of blockades.  I am not an expert regarding the law of the sea.  I am not an expert regarding the San Remo Manual.  So I am genuinely open to being convinced that my argument is wrong.

Readers?  Your thoughts?  (And be warned that I will delete nasty or irrelevant comments.  I’m trying to encourage genuine academic debate over the legality of the blockade; I have no interest, at least in this post, in debating the normative or political merits of Israel’s actions.)

UPDATE: As a number of commenters have pointed out, Lincoln’s blockade of the Confederate States of America (CSA) during the Civil War is a relevant historical precedent.  But I think that the Civil War blockade actually supports the argument I’ve made above.  As noted in the Lincoln section of the University of Virginia’s Miller Center of Public Affairs, the international community viewed the blockade as an act of war that required the CSA to be formally recognized as a belligerent, thus effectively transforming what was previously a NIAC into an IAC:

The first crisis occurred when England issued a proclamation of neutrality, which rested upon the logic of the Union’s declared blockade. According to English reasoning, although Lincoln proclaimed the rebels to be insurrectionists and thus not recognizable under international law as a belligerent power engaged in war, his declared blockade was an act of war, which would have to be conducted against a sovereign state. Thus Lincoln had actually granted belligerency status to the Confederacy and thereby forced foreign powers to do the same. By proclaiming neutrality, England afforded the Confederacy the status of a belligerent power. Other European nations followed England’s lead. Belligerency status gave the Confederacy the right, according to international law… to contract loans and to purchase arms from neutral nations. It also allowed England to provide safe harbors for both Union and Confederate warships and merchant vessels, to build blockade runners and warships for the Confederacy, and to formally debate in Parliament the merits of active intervention.

L.C. Green, one of the great IHL scholars, agrees with this analysis.  If this is still the state of the law — and I don’t know whether it is — it would be possible to argue that Israel’s conflict with Hamas is an IAC and Israel is thus entitled to blockade Gaza.

But there’s a catch — and a big one.  If the “cost” of the blockade is formally recognizing Hamas as a belligerent, maintaining the blockade would mean recognizing Hamas fighters as privileged combatants.  (Just as the armed forces of any state are privileged combatants.)  That would be fundamentally unacceptable to Israel, because Hamas fighters would then be entitled to attack Israeli combatants and would have to be treated as POWs upon capture.