Hasakah, Ramadi, Palmyra — they all illustrate how ISIS strikes back whenever the group takes a hit both to boost the morale of its own fighters and to give the sense it remains undefeated even when it does suffer defeats. “Carry the battle to them. Don’t let them bring it to you. Put them on the defensive,” was Harry Truman’s take on how to conduct warfare. And that is exactly how ISIS fights.

With the Ramadi assault, the ISIS planners have also set up the circumstances for more trouble for the Iraqi government in Iraq’s western Anbar province. Iraq’s Prime Minister is now saying he will deploy Shia militias to the city to mount a fightback — but that is likely to roil more Sunnis in a province that they dominate and undermine efforts get the tribes that are aligned with ISIS to defect.

Meanwhile with the expansion of affiliates in Libya, Afghanistan and Libya, and stepped up efforts to inspire terrorist activities, whether by lone wolves or more directed agents of terror, in the United States and Europe ISIS has even more options. Analyst Jonathan Schanzer of the Foundation for the Defense of Democracies, a Washington-based think tank, suspects ISIS will answer Friday’s Delta Force raid with a terror attack in the West to try to blunt the psychological warfare edge the US secured with the nighttime commando assault. “Such strikes could invite more attacks here, against the homeland,” he says.