Israel's actions in the Gaza strip aren't surprising or shocking in the least. They have a clear cut casus belli and Hamas should be punished for its actions. That isn't why this particular conflict is so troubling: Netanyahu is using the threat of Hamas' tunnels as a justification for formally withdrawing his (misleading) public support of a two state solution and this comes as a Naftali Bennet is pushing for a de facto annextion of the West Bank. Something is rotten in Israel.
I'm an "anti-Zionist" because I am concerned for Jews who have no interest in living in an Israel that treats them as gentile-loving traitors. Israel legitimizes anti-semitism as a valid worldview every time it defends its settlements. Every time it displays ultra-jingoistic behavior by bombing Gaza hospitals, imprisoning those who work for NGOs and bullying the US, it makes the world a much darker place for Jews.
So you consider anti-semitism a valid and legitimate lens through which to look at the world? Wow...
Anti-semitism is evil. If you're serious about combating it, it's of the utmost importance to consider what factors nurture anti-semitism. Israel's actions have unquestionably turned millions towards anti-semitic beliefs.