"It seems to be a question of interpretation and not a clear cut case of legal or illegal."


And therein lies the problem Keith

Opinio Juris is a forum for informed discussion and lively debate about international law and international relations. It was founded by Chris Borgen, a law professor at St. John's University Law School, who started the site with Peggy McGuinness of the University of Missouri Law School and Julian Ku of Hofstra Law School

Here Prof Kevin Jon Heller is currently a Senior Lecturer at Melbourne Law School admits he is confused



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 international armed conflict (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 **


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"

full article

** it is claimed by many - including the Government of Canada that -

"This construction (the 'seraration barrier')is contrary to international law under the Fourth Geneva Convention.
Canada not only opposes Israel's construction of a barrier extending into the occupied territories, but also expropriations and the demolition of houses and economic infrastructure carried out for this purpose."