It is clear from this article, and Mr. Fallaci has been around around a long time, that the 'Islamic' squatters as you call them have some useful idiots among the Europeans, all to willing too aid the anti-Semitic agenda. Not a pretty sight.
I submit they side with the Palestinians because they are leftist. And leftists will always side with the "downtrodden"...the "indigenous"...the "oppressed"...etc. In short, their view of the Palestinians.
If anything, they are opposed to the Israelis because they consider the Israelis Jews the "white guys"- and these self-hating Euros (and believe me, we have an equal, if not greater, percentage of them here in the US) will always side with the "people of color" over Whitey.