In the hours after the Trump administration announced that it would begin “aggressively” revoking the visas of Chinese students, the line to apply for new visas at the United States Embassy in Beijing still stretched down the block on Thursday.

But for many of the hopefuls — including some who walked out of the embassy with their visa applications approved — any celebration was laced with a mix of anxiety and helplessness.

“What now? Something new every day?” said Li Kunze, 18, who had just successfully applied for a visa to study as an undergraduate. He had not heard the news until he left the embassy. “I don’t even know if they can give me this visa that I just got.”

He sighed. Since it was too late to apply elsewhere for his undergraduate years, “I can only brace myself,” said Mr. Li, who plans to study applied mathematics. But, “in the future, if I can avoid going to the United States to study, I will. They make people too scared.”

The scene outside the embassy captured the complicated feelings many Chinese students have toward studying in the United States. Hundreds of thousands still go each year, lured by the promise of a world-class education. Some also have deep admiration for America’s professed values of openness and diversity.

But they must reckon with the fact — made clearer by the Trump administration every day — that many in the United States may not share that admiration.