I've followed this thread with interest.
Everyday I try to think about this conflict and I really feel myself being pulled in different directions. The whole situation is so suffused with hatred and emotion on both sides that it is difficult to see clearly.
On the one hand, I have an instinctive gut reaction when I see pictures on television of burning flags with the Star of David and swastikas on them. I do see a hostile and simmering antisemitism in the arab/muslim world. When I was working with refugees, I used to receive emails from a colleague working in humanitarian aid for a muslim organisation which would along with other news from the area would sometimes include comments such as "I see the brothers killed another four cockroaches this week" - which I found really horrific and offensive - gloating over the murder of Israelis.
On the other side, we have a situation where Israel seems almost like an automaton devoid of emotion or conscience. When a human abuses another (for eg domestic abuse or child abuse) they are often only able to do it by dehumanising their victim, by denying the reality of the victims experience. I think that this is what happened here.
I think what Israel should be doing for starters is flooding the occupied territories with aid: food, water, medicines. I also think that the response has been disproportionate.
Personally I feel angry when I hear either side of the polarized views - there is so much emotional propaganda and wrongdoing. I have given up personally trying to work it out in my head and now approach the situation in terms of "Who is suffering? What can we do to alleviate it?"
I think the answer is quite obvious and despite in my opinion legitimate fears about future security, Israel should be a "mensch" and do the right thing.
However, I would not attend such a march purely because I have serious misgivings about the far left and their idealism being a conduit for the reemergence of antisemitism. As someone else has pointed out, if you think there weren't antisemites in that crowd you are sadly mistaken.
I think I would have attended a peace march calling for cessation of all violence in the area and protection for civilians esp women and children though.