In a week, ISIS went from growing its self-proclaimed Islamic State to trying to break another fragile state—Iraq—by sowing fear and sectarian hatred.

In the last week, ISIS has slaughtered brides, shoppers, and good Samaritans in their campaign to split the Iraqi state. On Tuesday, at least 63 people were killed and another 100 plus injured in Baghdad in three bombings, all of which struck open markets.

In all, more than 200 people have been killed in the last week in what has become the deadliest spate of bombings to strike the capital in years. ISIS has stormed soccer fans watching a match in the northern city of Balad, targeted women at the hair salon in northeastern Baghdad getting ready for their wedding day and on Tuesday, a fruit and vegetable market in the neighborhood of Dora.

The sudden rise in ISIS attacks, U.S. officials believe, signals that the terror group no longer is committed to territorial expansion. Rather, ISIS is looking to keep Iraqi government troops from hitting ISIS’s local capital of Mosul—by putting those forces on the defensive in Baghdad. If Iraqi security forces are struggling to stop unending attacks on Baghdad, the logic goes, they cannot move hundreds of miles north to reclaim Iraq’s second-largest city. In recent weeks, amid growing anti-government protests, the Iraqis have bolstered forces in Baghdad, dedicating half of its troops to defending the capital, a U.S. defense official said.

“Although ISIS ultimately wants to capture Baghdad, they seem to understand that they’re not capable of launching a successful campaign against the city now—it would be a completely different thing from capturing Fallujah and Mosul, not the least because Baghdad is so Shia-dominated,” a congressional aide to The Daily Beast. “So ISIS is doing as much as they can do against the city at this time, which is to try to sow chaos, degrade security, and make people feel vulnerable through these scattered bombings and attacks.”

The return of regular bombings undermines a second set of plans—to cool the tensions between Sunnis and Shia under the leadership of non-sectarian Iraqi Prime Minister Haider al Abadi.

“While we believe [ISIS is] on the defensive and they are back on their heels, they still remain a legitimate threat. They’re a dangerous enemy, and they’re also smart,” Army Col. Steven Warren, the spokesman for the U.S. effort in Iraq and Syria, told Pentagon reporters Friday. “And so, they’ve seen an opportunity here to create discord, to create disharmony. You know, these strikes went straight into, in many cases, heavily populated Shia areas. And really focused on civilian women, children—complete civilians, not in any way, shape or form someone that could be considered a combatant or even a threat to ISIL in any way.”

"As it faces mounting losses of territory, ISIL, as it often does, conducts counterstrikes,” a U.S. intelligence official told The Daily Beast, using Washington’s preferred acronym for the group. “In this case, it is seeking to offset losses of territory with public relations and social media attention."

Iraqi officials are pointing the finger of blame at the Sunni-dominated city of Fallujah, just one hour west of Baghdad. Under ISIS control longer than any other Iraqi city, government officials suspect the terror group is sending suicide bombers into Baghdad’s Shiite neighborhoods along a highway the U.S. military knew as Route Tampa during its many battles in Fallujah.

Meanwhile, Shia leaders with their own armed forces—including rebel cleric Muqtada al Sadr—have also mobilized their fighters to secure the capital. There are thousands of so-called “population mobilization forces” patrolling Baghdad, creating a capital now is governed by various fiefdoms.

“We are seeing the further fracturing of the population of the Shiite militias,” Christopher Harmer, an analyst at the Washington-based Institute for the Study of War, explained to The Daily Beast.

Abadi, the Iraqi prime minister, “seems to want to govern in a moderate way,” Harmer added. “But he is presiding over a society that is completely fractured.”

U.S. officials have called the ISIS bombings act of desperation. Privately, they are worried about the implications of them on an already fragile Abadi government and his divided capital.

—with additional reporting by Shane Harris