“I first went to China to study myself in the fall of 1989,” said Sophie Richardson, the China director of Human Rights Watch. “Twenty-five years later, it’s much easier for mainland students to go to Australia or the U.S. and study, and yet they are in some ways and in some cases as restricted or as surveilled as they would be if they had stayed at home. That, to me, is not the right direction for us to be going.”

The students’ assertiveness has posed a challenge not only to Australia’s universities but also to its broader society, which prides itself on being a tolerant, multiethnic melting pot. The Australian news media has given the episodes intensive, often negative coverage, portraying the students as brainwashed or under the thumb of government agents. A backlash has appeared in the form of racist anti-Chinese scrawlings on campuses.

Behind the attention is the deep anxiety that many Australians feel toward an emerging Asian superpower that is both their country’s biggest security challenge and its largest trading partner. The episodes have added to existing concerns about Chinese influence in Australia.

“We need to be very conscious of the possibilities of foreign interference in our universities,” Duncan Lewis, the head of Australia’s domestic intelligence agency, warned lawmakers last month. “It can go to the behavior of foreign students, it can go to the behavior of foreign consular staff.”

Concerns about the role of the roughly 164,000 Chinese students in Australia have become particularly acute as revenue from foreign students has become a major driver of its economy. Education is the country’s third-largest export (after iron ore and coal), and many Australian universities now rely on full-fee-paying international students, of whom nearly 30 percent are from China, to subsidize domestic students and academic research.

As a result, educators and other experts say, universities and faculty members have become especially vulnerable to pressure from Chinese students.