Two suicide bombers attacked the interior ministry complex in Ankara on Oct. 1—the first attack in the Turkish capital since Mar. 2016. Later that day, the Kurdistan Workers’ Party (PKK) claimed responsibility for the “sacrificial action.”

The incident must be seen in the context of the military operations against the PKK in neighboring Iraq. Indeed, PKK-linked media charged that the location and timing of the Ankara attack sent a message to Turkey about its cross-border bombings.

Yet, the military campaign against the PKK in northern Iraq will likely only intensify following the Oct. 1 attack. As Turkish President Recep Tayyip Erdogan said shortly after the blast, “We will continue our fight, both...