Khairat el-Shater, the leading strategist of the Muslim Brotherhood, offered a stark warning last Tuesday as he prepared for this weekend’s final round of the presidential election: Egypt can make its transition to a new order the easy way, or the hard way.

What’s ahead definitely is not going to be easy following Thursday’s court ruling that will dissolve Egypt’s new parliament, dominated by the Brotherhood, and allow a symbol of the old regime to challenge the Brotherhood’s candidate in this weekend’s polling.

The easy way, in Shater’s view, would be for Mohamed Morsi, the Brotherhood’s candidate, to win a fair election, unclouded by the legal uncertainties that emerged Thursday. In that case, Shater promises a broad unity coalition, a free-market “renaissance,” a pitch for foreign investment and a gradual transition away from the police state created by deposed President Hosni Mubarak.

Shater was conciliatory when he talked about a Brotherhood victory. “Egypt is too big a responsibility for one group to lead it. It has to be a coalition,” he asserted. He didn’t talk about a Muslim state; indeed, the word Islam barely surfaced in the 90-minute conversation. Yet the conversation was scary when he talked about what would happen if the Brotherhood should lose.

But turmoil is ahead for Egypt, he says, if Ahmed Shafiq, a hard-line former prime minister, appears to win Sunday’s runoff. I say “appears” because Shater was already accusing Shafiq of “soft-rigging” the polls before Thursday’s court ruling. And he made a not-so-subtle prediction that if the Brotherhood’s rival should win, there will be violence.

The Egyptian people “will not accept Shafiq as president,” he said flatly. “From the first day of the announcement, people will be back to Tahrir Square. If the choice of the people is to protest, we will join the people.” He warned that foreign countries shouldn’t make quick moves to recognize Shafiq.

“The coming revolution may be less peaceful and more violent” than the one that toppled Mubarak, Shater predicted. “It may be difficult to control the streets. . . . Some parties, not the Muslim Brotherhood, may resort to further violence and extremism. . . . When people find that the door to peaceful change is closed, it is an invitation to violence.”

Many Egyptians in the middle — unenthusiastic about either the Brotherhood or the return of the old guard — were preparing for this weekend’s election with a sense of dread. Hani Shukrallah, a prominent journalist who edits Ahram Online, offered a description I heard several times here: “It’s a choice between cholera and the plague — between a Muslim state and a police state.”

The Obama administration, which has made a huge bet on the Egyptian revolution, is preparing for both outcomes. If Morsi wins, Washington will rush a quick package of economic aid, knowing that he must show economic progress. If Shafiq wins, the U.S. expects a tough crackdown on street protesters and will work to keep the confrontation from becoming too bloody.

The White House, perhaps surprisingly, thinks a Morsi victory would be the best for Egypt’s economic transition though it would raise some prickly foreign policy issues.

The future of parliament is a wild card. Some analysts are forecasting legislation by military edict until a new parliament is elected; others aren’t so sure. But the likelihood of renewed violence in Egypt increased sharply after the court ruling.

Shater may be the Brotherhood official Washington has cultivated most, seeing him as the likely power behind the mild-mannered Morsi. He’s a big, imposing man with a bushy beard and a voice that rises almost to a shout when he warns about the dangers of a Shafiq victory.

His description of the Brotherhood’s economic plans is straightforward and fairly sensible. He knows that Egyptians have to get back to work after the yearlong upheaval that followed the revolution, and he said that a combination of better social-welfare measures and pressure from individual members of the Brotherhood in the factories will stop the strikes. He knows, too, that Egypt needs foreign capital, and the new government plans to work with the International Monetary Fund and private investment banks. But all that may be on hold with dissolution of the parliament.

On foreign policy, Shater offered a hint of conciliation when he says the new government would be ready to keep on some top intelligence officials, who have won high marks from intelligence chiefs in the United States, Israel and Europe. But this, too, is probably less likely in the polarized situation following the court ruling.