YEREVAN, Armenia — Nikol Pashinyan, who led the nonviolent protest movement that improbably toppled the government of Armenia, had just ended a brief interview and headed into another room when he whirled around.

“Would you like to eat?” he asked, beckoning to a table scattered with plastic cartons holding takeout pork kebabs wrapped in paperlike bread, as well as tomato and cucumber salad. “This kind of lunch is the usual for us for the past month; we have not gotten back to civilized ways.”

If whirlwind events of the past month are any guide, Armenia might never get back to its old ways, civilized or not. On Tuesday, Mr. Pashinyan became Armenia’s interim prime minister, when a Parliament dominated by his political foes elected him by a 59-to-42 vote.

After vowing to remake the country’s political and economic systems, Mr. Pashinyan told a cheering throng in the central Republic Square in Yerevan, the capital, that, “Your victory is not that I was elected as prime minister of Armenia; your victory is that you decided who should be prime minister of Armenia.”