If you are trying to influence the debate about Israel, who do you speak to?
Do you speak to Zionists?
Typically, no, because they already agree with you. It may still be valuable at times to further educate supporters of Israel and to energize them, but they do not need your persuasion.
Do you speak to anti-Zionists?
Again, the answer is usually no. There is nothing that you are likely to say that will change their opinions so why waste your time and energy unless you enjoy debate. The exception is if the discussion takes place with an audience that does not have a set position. In that case, bystanders may learn something if your arguments are persuasive.
The main audience will be your peers who know little or nothing about Israel and are open to learning.
The toughest audiences today are self-defined liberal/progressives who often focus on civil and human rights issues and are disturbed by Israeli policies, but usually do not know the context for those actions. They must be addressed in the language of liberal/progressive politics.