Understanding whether nation-state information operations on social media have real-world effects is an important question. Previous research has shown that Russia targeted American divisions along issues of race, however, it did not have any impact on political attitudes and behaviors of Twitter users. We identify Islam as another issue on which Russian trolls posted inflammatory content and study the causal effect of their tweets about Islam on anti-Muslim hate crimes in the United States. Using events, holidays, and weather conditions in Saint Petersburg, where a key Russian troll organization is based, as an exogenous source of variation in content production, we find that increases in anti-Islam activity by Russian trolls led to increases in anti-Muslin hate crimes in the United States. In our preferred specification, a one standard deviation increase in log(Russian tweets about Islam) predicts a 30% increase from the mean rate of anti-Islam hate crimes for US divisions with average exposure to IRA trolls. Our results have policy implications for combating information operations and safeguarding the public security.