It's the same as in Northern Ireland a few years ago.
The people inside the communities in Northern Ireland were uniting across the sectarian divide, uniting to demand peace. Some people outside the province were demanding the same.
The efforts of those people were constantly undermined by armchair commentators in the UK and America who had no direct knowledge of what it was like to be caught in the middle, and took sides without actually knowing what the "cause" they supported actually meant to the people it supposedly "benefited" - i.e. the people who were menaced by the very people being funded to protect them.
I guess its all in how you interpret it.
You see you view that as being a great thing Jews and Muslims gathering to oppose the war.
I see it as Jews who arent smart enough to figure out that these same Muslims want them dead and if given the chance would kill them on the spot.
Certainly they stand side by side in condemning Jews, but why arent they protesting the Hamas shooting rockets over to kill Jews? How many Muslims do you suppose would stand beside Jews protesting Hamas shooting rockets and Missiles at Israel.?
Unfortunately in this case the common ground is disdain for the State of Israel