Bangladesh, April 23 -- The modern world is more connected than at any other point in human history. People, goods, money, and ideas move across borders with ease. This global connection has brought major benefits, including economic growth, cultural exchange, and greater access to information. However, it has also created new and serious risks. One of the most dangerous of these is the spread of violence that is supported, guided, or encouraged by states but carried out by hidden agents in other countries. This type of violence must be met with a clear and firm response: zero tolerance.

Using violence as part of political conflict is not new. For centuries, states and groups have used secret operations, spies, and outside fighters to we...