This has been discussed in numerous threads in this forum. 99% of people who are anti-Israel really just hate Jews. They have no genuine knowledge of the issue and no dog in the fight and yet they just pull this strong anti-Israel stance from thin air.
There is little one can say to change this. Here is an excellent link to the myths and facts regarding the Israeli-Arab conflict.
http://www.jewishvirtuallibrary.org/jsource/myths2/mftoc.html