Seven years after the attacks of Sept. 11, 2001, plunged the United States into a global War on Terror — and with more than 170,000 U.S. troops still fighting on two foreign fronts — recent polls show American voters fixated chiefly on the economy, not terrorism or national security.

Yet the next president will confront a broad range of potential terrorist threats: from the ongoing assault by the Taliban and Al Qaeda, the terrorist group that executed the Sept. 11 attacks, to Hamas and Hezbollah in the Middle East; from invisible biological, chemical and cyber attacks to Russia’s still unsecured nuclear arsenal.

On the campaign trail, the candidates’ talk on terrorism has tended to focus almost exclusively on the two war zones. ...