This video is brilliant:
In it, David Sable, one of the top marketing and "branding" professionals explains why Israel cannot (and does not) win the hasbara (propaganda) war with the Palestinians.
Sable, an Israeli-American, who is emphatically pro-Israel explains that you cannot market a bad product and that Israel's most controversial policies (Gaza, etc) are simply indefensible, no matter how you frame them.
His suggestion is that friends of Israel stop shooting the messenger and start adopting policies that are defensible because they are moral.
I cannot recommend this too highly. Sable is clearly a very thoughtful guy. If he can only make Israelis and their American friends understand that defending the indefensible will never ever succeed.