Domestic Terrorism Threat Lingers 20 Years After Oklahoma City

It is 20 years since the United States suffered its worst act of domestic terrorism, the 1995 Oklahoma City bombing. Despite the intense focus on jihadist terrorism in the wake of 9/11, domestic terrorism remains a persistent and unrelenting threat to the United States. But as deadly attacks in Norway, the United Kingdom and Canada demonstrate, domestic terrorism is not just an American problem.