Home Grown and Transnational Terrorist Attacks Increasing in US and Europe

FBI bomb-disposal unit. Public domain, via Wikimedia Commons.

Across the United States and Europe, Islamist terrorist attacks are increasing in frequency. Some perpetrators are homegrown violent extremists radicalized domestically by ISIS propaganda and acting without direct foreign instruction.

Others are connected to Shia militant networks linked to Iran, operating either as state-directed proxies or as individuals motivated by Iran-axis grievances.

This common threat environment...