WASHINGTON — As he sought to rally the world behind a renewed attack on terrorism, President Obama argued on Thursday that force of arms was not enough and called on all nations to “put an end to the cycle of hate” by expanding human rights, religious tolerance and peaceful dialogue.

But the challenge of his approach was staring him right in the face. His audience of invited guests, putative allies in a fresh international counterterrorism campaign, included representatives from some of the world’s least democratic and most repressive countries.

The three-day White House conference on violent extremism that Mr. Obama wrapped up on Thursday provided a case study in the fundamental tension that has bedeviled the American struggle with terrorism since the attacks of Sept. 11, 2001. While Mr. Obama has concluded that radicalism is fueled by political and economic grievance, he has found himself tethered to some of the very international actors most responsible for such grievances, dependent on them for intelligence and cooperation to prevent future attacks.

“There is a very profound conceptual disagreement about whether the best way to counter violent extremism is through human rights and civil society or through an iron fist,” said Marc Lynch, director of the Institute for Middle East Studies at George Washington University. The Obama administration wants “to project the human rights side, but you look at the people they’re working with and fighting alongside, and there’s a lot more to it than that.”