This CSIS brief examines the state of terrorism in the United States. It asks two sets of questions. First, what are the most significant types of terrorism in the United States, and how has the terrorism threat in the U.S. homeland evolved over time? Second, what are the implications for terrorism over the next year?

To better understand the implications of right-wing terrorism in Europe, this analysis asks: how significant is the threat from right-wing terrorism in Europe, particularly compared to other terrorist threats?

There is growing concern about Iranian threats to Persian Gulf countries, particularly Saudi Arabia. This briefing paper assesses the Iranian threat to Saudi Arabia by answering several questions. What types of strategies, tactics, and capabilities could Iran use against Saudi Arabia? What are potential critical infrastructure vulnerabilities in Saudi Arabia, and how serious are they?