SANTIAGO, Chile — With a torrent of criticism over her government’s response to the earthquake and little more than a week to dispel it before leaving office, President Michelle Bachelet on Wednesday intensified her efforts to provide help to the hundreds of thousands of people affected by the disaster and publicly began the fight to preserve her legacy.

In the morning, Ms. Bachelet seemed a portrait of strength, reassuring the leaders of Chile’s most powerful business association that the country had the reserves to rebuild its shattered infrastructure, and later cheering on volunteers who had begun building temporary houses for those displaced.

Then, during an extensive interview on Chile’s most popular radio station, the typically poised president vigorously defended the way her government had managed the crisis and gave way to emotion, saying, “Everyone claims to be a general after the war.”

“Enough with assigning blame,” she said.

Observers said the impassioned hourlong exchange was one more sign that just days after one of the most powerful earthquakes in recorded history, Chile’s political landscape had shifted as well, exposing fault lines that threaten to plunge a country that has enjoyed decades of stability into the kinds of polarizing struggles still experienced by some of its neighbors.