Namely Hamas its refusal to except Israel's right to exist. It is impossible for a solution. When you consider that Hamas has committed 8-10 thousand "War Crimes" by firing rockets and mortars into Israeli civilian towns( virtually without criticism or condemnation), I don't see a solution on the horizon. Add to that the anti Semitic indoctrination of their children for the last five generations how can you expect any serious movement on this issue? The blockade a peaceful response to violent attacks is a creative solution to a national threat to Israel. Just like the Cuban missile crisis in the 1960's and the U.S, blockade of Russian ships trying to deliver missile's into Cuban that posed a threat to the USA. It is the right step by Israel that can be changed when Hamas agrees to live in peace, or at least, not look for war. The USA was right in Cuba and Israel is within its rights here.
Law expanding definition of terrorist activity passes first Knesset reading (Haaretz)
from the article: World leaders at G8 summit: Current Gaza tensions unsustainable