Help wanted: Excoppty at Ivy League university. Successful candidate for presidency has ability to clock-in sweatshop hours; tolerate laser like scrutiny from trustees, faculty members, alumni, parents; raise billions of dollars; work under constant threat of termination. Competitive compensation.

Given the stressful state of affairs for Ivy League presidents, that might as well be the job posting for Cornell University’s next president. The abrupt resignation of Jeffrey Lehman after only two years at Ithaca is the culmination of an unusually trying year for leaders of some of America’s most prestigious universities.

Recent months have seen Columbia University’s Lee Bollinger beating back criticism over his handling of a controversy surrounding the university’s department of Middle East studies, and Harvard University’s Lawrence Summers stung by a vote of no confidence from his Faculty of Arts and Sciences. And now, Cornell must deal with the fallout of Mr. Lehman’s departure following one of the shortest presidential tenures in Ivy League history.

“Being a college president these days is a difficult job,” the chairwoman of Harvard’s Seminar for New Presidents at the Graduate School of Education, Judith McLaughlin, said yesterday. The seminar provides a sort of basic training to more than 40 newly minted presidents each summer on avoiding hazards that most commonly afflict a university’s chief executive.

For Ivy League presidents, who run institutions with particularly high visibility, the strain can be even greater.

As Mr. Bollinger put it in a speech June 1 before the university’s Kraft Center for Jewish Life, “This has been a difficult year, of course.”

Said Ms. McLaughlin: “The days when presidents basically reported to trustees what they had done, and trustees nodded their heads and said ‘that’s nice,’ have definitely passed.”

In the cases of Messrs. Bollinger and Summers, the obstacles were to some degree foreshadowed, as long-simmering disagreements within the university bubbled over. At Columbia, concern over the political direction of the Middle East department turned to an uproar after the release of a film in which professors were accused of verbally attacking students for their views. At Harvard, deep-seated resentment over Mr. Summers’s leadership style among some faculty members led to calls for his resignation following a speech suggesting the possibility that innate differences in intelligence between men and women explained the latter’s relative lack of representation in science and engineering.

At Cornell, the reasons behind Mr. Lehman’s resignation aren’t clear. According to one trustee, Andrew Tisch, Mr. Lehman saw his relationship with Cornell’s board gradually deteriorate in the last several months.

“The board has known about some issues for the last few months,” Mr. Tisch, who is chairman of the executive committee of the Loews Corporation, said. Disagreements between the 48-year-old president and the board “sharpened” more recently, he said.

Trustees and university officials were vague about the sources of those disagreements. Mr. Tisch called them “philosophical differences.” Each party, he said, has a different “long-term vision for the university.”

“It’s not a complicated story,” Mr. Tisch said. He said he did not agree with the board’s assessment “100%” but was “going along” with the president’s and the board’s determination.

The differences were so great, apparently, that Mr. Lehman won’t stay in office until his replacement is installed – his predecessor, Hunter Rawlings, who served eight years, agreed to serve as interim president. Mr. Lehman will remain as a tenured law professor.

Mr. Lehman broke the news of his resignation in his state-of-the-university address Saturday. He likened himself and the board to two pilots in the same plane wanting to fly in opposite directions, albeit to the same destination.

A spokesman for the university, Tommy Bruce, said Mr. Lehman described the course of his presidency as “20 bumps on the road.” Mr. Bruce said he could not waver in his explanation from the way the “president wants us to characterize this.”

The chairman of the board, Peter Meinig, in his written announcement of Mr. Lehman’s resignation, also chose not to delve into specifics.

“While much has been accomplished over the past two years,” he wrote, “we believe that this decision is in the best interests of Jeff and the University and all of its constituents.”

Mr. Lehman, former dean of University of Michigan’s law school and the first alumnus to serve as the university’s president, began his tenure July 1, 2003, delivering an inaugural address in which he promised to turn Cornell into what he called a “transnational” university. He assumed office fresh from a Supreme Court victory on affirmative action in admissions. Representing the Michigan law school as a defendant in the twin University of Michigan cases, Mr. Lehman became a prominent spokesman for the cause of affirmative action in higher education. Mr. Bollinger was president of the University of Michigan when the policies in question were challenged.

Perhaps the most prominent controversy of Mr. Lehman’s tenure far above Cayuga’s waters was over a proposed parking lot the university wanted to build on a site called Redbud Woods. The university decided last week to halt construction of the 176-space lot in the face of student environmental protests, which in April led to the arrest of eight students for trespassing.

While Mr. Lehman was president, Cornell’s endowment, one of the more modest among the eight schools of the Ivy League, grew by about $1 billion to $4 billion. In 2003-04, Cornell alumni set a school record for gifts.

By far, Mr. Lehman’s most ambitious initiative was his “Call to Engagement,” an 84-page report for the university that he wrote based on conversations with faculty, students, alumni, and trustees. It contained sweeping recommendations about the school’s mission, including what it should teach students.

Mr. Bruce, the university’s spokesman, said that as president Mr. Lehman had to act as CEO of an enterprise, public official, and scholarly educator. University presidents like Mr. Lehman “have to be able to satisfy, to meet the needs and lead without issuing commands.”

“It takes a lot out of you,” Mr. Bruce said.