The problem is that the WBC merely requires you to be eligible for citizenship of a certain nation to represent them, while most other competitions require actual citizenship. Israel's laws allow any Jew (unless you're a convicted murderer or something, which baseball players probably aren't) to become a citizen. Plenty of naturalized citizens have represented Israel in international competitions before. But they moved to Israel and actually got citizenship, with all its responsibilities, including military service. They were, for all intents and purposes, as Israeli as someone born there. The Americans on Team Israel are not Israeli citizens. That's the difference.
It's also worth noting that Spain allows anyone whose ancestors fled the country during the Franco regime to be citizens, so numerous people of Spanish descent who never set foot in Spain in their lives represented Spain in 2013. Those people would have to actually move to Spain, become citizens, and under Spanish law renounce their other citizenship, to represent Spain at other competitions.
But other than athletes boycotting sporting events in the FFR I don't really have any RP ideas.
