It’s not the war against third world debt, but still.

Bono, the lead singer of U2 and a globetrotting activist for social causes, has become involved in a battle that may be as intractable as loan burdens in the developing world — a Manhattan co-op dispute.

One of his adversaries is a fellow rocker, Billy Squier, best known for 1980s songs like “The Stroke.” The two live in the San Remo, a storied building with twin towers that loom over Central Park West. (It is the same building that rejected Madonna in 1985 when she sought to buy an apartment.)

The dispute is over whether hazardous smoke from fireplaces, including Mr. Squier’s, is drifting from chimneys into the penthouse duplex where Bono lives with his wife and four children. About a year ago the co-op board banned the use of fireplaces throughout the building, angering fireplace owners, who love a pine-scented blaze in the city as well as their enhanced property values.

As with other co-op disputes, exact details are hard to pin down because these buildings are essentially private clubs run by a board of elected tenants, and anyone who airs grievances in public risks being ostracized in his own hallway, sometimes for generations. The San Remo, at West 74th Street, is home to many prominent New Yorkers, including Steve Martin, Steven Spielberg, the producers Scott Rudin and James L. Nederlander, and the writers Andrew Tobias and Marshall Brickman.