As the U.S. reintroduces oil and multisector trade sanctions on Iran on Monday, President Trump must anticipate Iran’s response. The Islamic revolutionary republic is highly likely to lash out in some violent or destabilizing fashion.

The evidence for this concern is already abundant. Since at least early October, European intelligence services have witnessed escalating Iranian preparatory actions toward near-term terrorist attacks on the continent. This threat environment must be taken seriously in that the Iranians have the capability and pedigree for terrorist attacks that would appear, by most analytical assessments, to risk far greater negative responses than they might earn in political dividends. Iran’s plotting of attacks in Europe also fits with its strategic interest in sending a message in a way that might not invite immediate and overwhelming American response.