Back in the 1970's the most effective way that Jews dealt with those who used Israel as a proxy to attack and spread hatred of Jews was to de-legitimize those who did these things. After enough ridicule they usually crawled back under the rock they came from. Might be a good idea to apply this today?
27 injured in fire, explosion at former air raid shelter in Hamburg, Germany (DPA)
from the article: Want to delegitimize Israel? Be careful who you mess with