In the aftermath of the latest incident in the ongoing effort to delegitimize Israel, I thought I'd comment on a few issues that have come up. I rarely have much to say about international law, because -- if it isn't obvious by now -- I regard it as largely a myth, when talked about as if it were actual "law." International law is not binding on states -- unless they voluntarily bind themselves -- except on the weak facing a coalition of stronger states willing to enforce their interpretation. Greater powers not only make international law, they can interpret it to their liking, or ignore it altogether in many instances. Having said that, there are long standing customs & traditions, generally accepted, that form part of what is called international law. Two such areas that fall into that category are blockades, particularly the naval variety, and civilian status.
Blockades are a feature of naval warfare that have not faded into obscurity and disuse. Some may have forgotten, but there was a massive effort to blockade the former Yugoslavia in the 1990s during the NATO intervention. According to the LA Times, NATO naval forces stopped and inspected 74,000 ships during that period. There are two main requirements for a blockade under international law. First, the existence of a blockade must be public. And second, it must be "effective." Effective means that it must be enforced. You can't declare a blockade, not bother to enforce it, and then occasionally & selectively stop some ships. That's harassment of shipping, not a blockade. Israel's blockade of Gaza is public. Under international law it is required to enforce it. If it doesn't do so, and just allows ships to violate it, the blockade itself no longer has legal existence.
Now we come to the always contentious issue of civilian status, which has been blurred by the prevalence of non-state, irregular combatants. Civilians have traditionally had protected status in warfare under international law -- even though that status is sometimes ignored in practice. But that protected designation rests on civilians as noncombatants. Civilians who take up arms against military forces lose their protection and become combatants. Until fairly recently, such civilians were actually labeled as illegal or unlawful combatants, and often subject to savage reprisal, such as summary execution. This is particularly true of civilians who abuse their protected status to ambush military forces.
There has been much howling from anti-Israel types, as well sympathetic bleating from their useful idiots who claim to support the Jewish state, about Israel killing "civilians" in the latest incident. Most of those making such assertions love to whine about international law, yet they ignore it completely as it relates to blockades and civilian status. To maintain a blockade, Israel is required to enforce it. The standard method of doing so is for naval forces to stop ships and inspect them. This requires that naval personnel board the ships in question, as was done 74,000 times by NATO in the 1990s. If the civilians aboard a ship which is stopped ambush or otherwise attack the boarders, they give up their protected status as civilians and become combatants. What weapons they have available or choose to employ are completely irrelevant. This would be true even if the ship in question was truly neutral, and not filled with terrorist supporters. A legal case could even be made that the Gaza flotilla was not comprised of neutral blockade runners, but rather was an enemy force attempting to break the blockade. In other words, those on board were in fact belligerents on the side of Hamas, and could have been sunk without boarding and inspection. But in any event, by their own actions the occupants of that ship gave up their protected civilian status when they chose to take up arms. The killing was entirely justified under long-recognized principles of international law -- not to mention basic common sense.