Boycotting Starbucks - it works! But….
Most of the coffee beans available in the US are imported from Brazil and Colombia, two countries that have close relationships with Israel and also support Israel. Boycotting Starbucks is one way, but buying Brazilian and Colombian coffees from other merchants might as well be profitable for producer and distributor chains based in Brazil and Colombia, which, in turn, benefit Israel through taxes and other monetary aspects. Therefore, my advice is also to ask the merchants where they get their coffee beans and ensure that they're not sourced from the aforementioned countries.