Even the law firms nimble enough to overcome the economic turbulence in recent years are not feeling invincible these days. The revenue looks good because costly litigation and specialized legal work are flourishing. But a generational divide is percolating just under the surface.

Rising associates in the millennial generation, worried about the future, are pushing up against the current law firm leaders, who are almost uniformly older men intent on staying for a few more years to top off very successful careers.

If any discipline is a window into the debate about balancing short-term profits over long-term survival, it is the legal profession, one of the most traditional businesses in the world. Forward-looking firms are revamping how they find new business and how to deliver the results more efficiently to their clients; some are experimenting with giving associates more leeway in building their own practices. But the largest portion of firms, by far, are holding firm to a time-honored business model in which associates climb a ladder to partnership over many years. It is a model, some who study the legal profession say, that could lead to a wave of firms splintering when current leaders retire.

“Some law firms could crumble after this generation because they don’t have a lot to sell to the next generation,” said William Henderson, a professor at the Indiana University Maurer School of Law, who has spoken and written extensively on the challenges facing the profession.