The writers are senior scholars at the Woodrow Wilson International Center. David Ottaway was The Post’s bureau chief in Cairo from 1981 to 1985.

Gen. Abdel Fatah al-Sissi, Egypt’s new deputy prime minister and de facto strongman, has called on Egyptians to take to the streets Friday to give the armed forces and police a “mandate” to crack down on violence and terrorism. With that call, the July 3 deposition of elected President Mohamed Morsi looks increasingly like a Nasser-style military takeover rather than the popular revolution Morsi’s secular opponents claim.

There was, of course, much opposition to Morsi and much support for his overthrow. Evidence is growing, however, that the campaign to collect signatures against him was not waged entirely by idealistic young Egyptians but instead had received ample support from state security forces. And now that the military is firmly in control, it is seeking to mobilize popular support to legitimize its political role.

There is a precedent for this in Egyptian history. In July 1952, the Free Officers carried out a coup d’etat, forcing King Farouk into exile and putting the military at the center of Egypt’s political life, where it has remained. Within a few months, the new government had banned all political parties and launched the National Liberation Rally, a mass movement to mobilize people in support of the revolution. Clashes between the Liberation Rally and the Muslim Brotherhood at Cairo University in 1954 became the pretext for banning the Brotherhood, which had initially supported the coup. Gamal Abdel Nasser, who was to emerge as president, also used the rally to increase his own popularity and shunt aside rivals favoring a return to multiparty rule.

The fact that Sissi’s call for popular mobilization in support of the military came one day after the anniversary of the 1952 coup, and in the wake of violence at Cairo University between pro- and anti-Morsi groups, makes that history strikingly contemporary. The call for massive demonstrations increases the likelihood that history will repeat itself — the question now is to what extent.

Already, this has made the road map toward democratic rule more difficult for Egyptians to follow. Friday’s demonstrations will amount to a public referendum for a crackdown aimed especially at the Muslim Brotherhood, contradicting the repeated calls by interim President Adly Mansour for national reconciliation.

These demonstrations will make reconciliation impossible. Turnout is expected to be large. Violence is quite likely, and no matter how incidents start, Morsi’s supporters are sure to be blamed. The military will claim that it has a popular mandate to put an end to terrorism and violence, and mass arrests of Muslim Brothers and other Islamists will follow.

It’s not clear whether this will become the pretext for banning the Muslim Brotherhood anew, as a violent, terrorist organization. Many lawsuits calling for its disbanding have been filed in Egyptian courts, and the Ministry of Social Solidarity has said that it is considering dissolving the group if senior Brotherhood leaders jailed since July 3 are found guilty of inciting violence. Egyptian courts have invariably ruled against the Brotherhood since 2012, making a guilty verdict all too likely.

The Obama administration has finally awakened to the fact that Egypt’s military has seized power. Accordingly, the United States has suspended the scheduled delivery of four F-16s. This is a step in the right direction, but it is not enough. The administration must insist that the will of the Egyptian people be measured by election results, not fanciful estimates of crowd sizes. To be accepted as truly democratic, the parliamentary and presidential elections the military has promised to hold within a few months must include Islamist parties, notably the Muslim Brotherhood’s Freedom and Justice Party. The presence of international observers — which the interim Egyptian government says it will allow — is merely window dressing if one of the major contenders is excluded.

Egypt is at a critical juncture. It can easily slide toward renewed authoritarian rule under military tutelage. Indeed, many supporters of the Mubarak regime cannot hide their glee at recent events. But such a regime would have to be even more repressive than Hosni Mubarak’s because Islamists are more mobilized, more organized — and angry.

But Egypt could choose to continue on the long road to reform, accepting pluralism and the uncertainties and compromises such a system imposes. The United States cannot make that decision. But U.S. officials must make clear to the Egyptian military and its supporters, as well as to Islamists, that Washington will choose its friends, and that they do not include regimes that curb popular participation at the polls in favor of street mobilization. This is a hallmark of authoritarianism, not democracy.