Shortly after dawn in Cairo today, as news spread that members of the Muslim Brotherhood had been slaughtered while saying their morning prayers, their spokesman told The Daily Beast that “the conscience of this country needs to wake up, and the conscience of the rest of the world needs to wake up."

The tragic events described by Gehad El-Haddad may just do that: the official death count is now over 40, allegedly including five children, one as young as 6 months old. El-Haddad blamed the military and police for firing on peaceful demonstrators without provocation.

The details may or may not be accurate. The military may or may not be responsible. In terse statements it has blamed an unnamed “terrorist group” for attacking the protesters outside the Republican Guard headquarters, or the headquarters itself, or both. The military says one police officer and one soldier died in the incident.

But in the Middle East as much as anywhere else, the first casualty of violence like this is truth, not just because it is hard to ascertain the facts even if you are in the middle of the confused and frantic action, but because people will believe what they want to believe. There’s a conspiratorial refrain that begins after each incident of politically fraught horror: “Ask yourself, ‘Who benefits?’” And each party will determine that its enemies benefit, therefore they must be held responsible.

Without in any way assigning blame for this massacre to the Muslim Brotherhood itself, any dispassionate observer must say that it will be the party that reaps the greatest short-term rewards from this incident. Nothing could better serve the Brotherhood’s purposes as it tries to win back the power that huge crowds and a military coup stripped away from Egyptian President Mohamed Morsi and his Brotherhood cronies last week.

Just a week ago, the organization was on the rocks. Tens of millions of Egyptians had signed petitions and filled the streets calling for Morsi and his men to step down. The military gave Morsi a 48-hour deadline to reconcile with his opponents and create a more open and pluralistic government. He refused, claiming his absolute legitimacy as the first president in Egypt’s history to win free elections. But on June 3 the military made its move, detaining Morsi, closing pro-Brotherhood media and arresting many of the party’s leaders.

The massive opposition hailed the move as an effort to reset the revolution that ended the 30-year rule of Hosni Mubarak in 2011. The Muslim Brotherhood, by far the best organized and disciplined party in the country, had subverted the will of the people, they said, citing multiple examples of the fascistic organization’s moves to put its own goals above the nation’s. It had lost the consent of the governed and therefore had to be thrown out.

But from the first, the Brothers played the victim card, sending contradictory calls for peaceful protest amid proclamations that they were ready to die as martyrs in the fight to see Morsi returned to power.

On Sunday, Haddad told us that the Brotherhood expected violent provocations, but would allow itself to be “a punching bag” rather than be dragged into violence. But it was hard to square that with the way the organization’s supporters attacked anti-Morsi demonstrators near Tahrir Square on Friday night.

This morning after the massacre Haddad told The Daily Beast the organization still insisted on nonviolent protest: "We don't have any other option, do we?" he said. "Since the incident, the main phase at Rabaa has been calming the crowd ... There is no controlling the cycle of violence if it erupts. So we have to stop it with our bodies and with our lives." But other voices are not so reasoning or so calculated, and many among the Brotherhood now shout for vengeance and threaten an uprising.

In the meantime, the ultra-religious Salafi party, Al-Nour, which had initially joined the new governing coalition, and which blocked the naming of moderate, secular Nobel laureate Mohamed ElBaradei as prime minister over the weekend, now declares that it is pulling out of the new regime. The massacre has thus consolidated Egypt’s Islamist parties once again.

The killings will also inspire violent factions on the fringes of the Islamist movements, many of which believe, along with Al Qaeda’s current leader, the Egyptian Ayman al-Zawahiri, that only war and terror can bring “true” Islamic rule to the region. These people were jailed under Mubarak, but they’ve been freed from prison since his fall. So Mohamed Soudan, the foreign-relations spokesman for the Brotherhood’s political arm, tells us none too subtly that the problem of violence “is not from the Muslim Brotherhood,” but the Army “should know that there are a lot of other Islamist movements who were being tortured by Mubarak, and they are out now. It will not be easy. I think we will find a lot of bloodshed in the country.”

Paradoxically, another group that may “benefit” from this spiral toward worsening violence is the Egyptian military and its leader, Gen. Abdel Fattah al-Sisi. In order to believe that, you have to buy into the notion—dismissed by many analysts—that the Army’s goal all along has been to take power into its own hands; that it had run the country in one way or another since the 1950s and it didn’t want to risk losing that role under a civilian government.

A more nuanced view is that the Army does not want to get its hands dirty by ruling, but it does not want to be ruled and lose its many prerogatives. Sisi had an agreement with Morsi that provided for just such an arrangement and, in effect, wrote it into the Constitution rammed through last year by the Muslim Brotherhood. That is one reason that until the end last week, Morsi reportedly could not believe Sisi would bring him down.

Whether by design or default, growing chaos will bring growing calls for the military to impose order, if necessary, by imposing ruthless martial law. And slowly, deliberately, the military is making the case that it has little choice but to act harshly.

Emad Gad, the deputy director of Egypt's largest think tank, the Al-Ahram Center for Political and Strategic Studies, claims that the Army had intelligence yesterday suggesting that the Muslim Brotherhood planned to "break into" the Republican Guard headquarters where it believes Mohamed Morsi is being held. The Brotherhood has been leading a demonstration outside the building since Friday, facing down the troops stationed on its perimeter. This was, precisely, the scene of the massacre this morning.

"There was a warning from the Army that the Muslim Brotherhood would try to invade" the building, Gad says. "If they succeeded, they will be inside the building. And if they didn't succeed, it will be a big problem, and they will use it to spread word and turn this into an international case."

Gad said that the Army has announced it has footage from the scene that "shows exactly what happened, so let's wait and see." There are also photos of dead and wounded soldiers, allegedly from scene. They’re circulating among Morsi opponents on social media right now, but their authenticity has not been verified.

The big losers in this post-massacre picture are the millions of Egyptians who’ve been hoping to build from their revolution a modern, relatively liberal society with genuine democracy and freedom. In Tahrir Square, the epicenter of Egypt’s political earthquakes in the last year and a half, the mood turned ugly over the last 24 hours. Many in the crowd started venting their anger on foreign television crews. Mobs accused the journalists of undermining their revolution by calling it nothing more or less than a “coup.”

But the wiser voices in the movement know that, now, they face much graver problems than semantics. The Egyptian public may well start to sympathize with the Brotherhood’s victims, especially if the account of children being killed proves true—and even if it does not.

Ahmed Hawary, a spokesman for the new political front and a member of ElBaradei’s party, deplores the violence on all sides and regrets the deaths this morning. But “the Muslim Brotherhood was rooting for such an incident,” he tells us. The organization’s supporters started clashes all over the country in recent days so “the Army would respond with full force,” says Hawary. “The Army should have been much smarter than to use lethal force.”

“We as a society and a revolution and an opposition are going to push as hard as we can for reconciliation, and for the inclusion of everyone,” says Hawary. “I don't think we should be held hostage to a never-coming inclusion project between the Islamist current and the rest of the people. They are either on board or they're not.”

In fact, Egypt’s revolution is far from over. But it is becoming a zero-sum game, where no party can win without others losing, and everyone is choosing sides.

—With Sophia Jones in Cairo.