The Israeli government is able to pursue its horrible policies because of a lack of support for palastinian people.
Preventing protest in powerful nations stops public opinion changing. Public opinion allows the political establishment to continue to avoid historical responsibility.
If western nations drop support of Israel and start using sanctions etc it would be much harder to destroy Gaza.
I feel like this would need protests well beyond the scale I can imagine any of the populations in these nations mounting, and that they'd have to be backed by widespread blockades & strikes.
But mostly that very little would slow Israel down, short of the US intervening militarily in the next few hours.
I understand, today my own nation votes to slap down a hand outstretched in peace and warmth. In my own state police deploy anti terror powers to crack down on anyone attending a rally against Israeli militancy.
But if we give up nothing will improve, and everything good we have started small and grew into unstoppable movements.
Am lucky on this one, in that my country is generally supportive of Palestinians and even our neoliberal government has been critical of Israel's behaviour, now and also in the past. It is unlikely that they'd ban the protests.
Though if they did, it could easily result in far more people taking to the streets.
Wishing you all the best in your endeavours, wherever you are.