WATERVILLE – Former British Prime Minister Tony Blair on Sunday called on Colby College’s Class of 2012 to resolve injustices and change the world through international cooperation.

In his address, Blair challenged the 465 Colby graduates to help the disadvantaged in their own country and abroad.

A small group of anti-war protesters briefly disrupted Blair’s speech. Police removed three protesters who began shouting from campus and arrested a Bangor man. A few other people with anti-war signs stood silently and stayed for the duration of Blair’s address, which didn’t acknowledge the demonstrators.

Blair told graduates they should pursue “noble causes,” such as saving the millions of people in Africa who continue to die from preventable diseases.

“Compassion is as important as ambition. So don’t just choose a career, choose a cause,” Blair said.

He also touched on inequities in the United States, saying there are people who haven’t been given the same opportunities as the Colby graduates.

Those who are given the tools to be leaders have a responsibility to address these wrongs, Blair told graduates. He said “sick people who don’t get health care” are one example of the people whose lives graduates should strive to better.

To achieve these goals, graduates must never stop learning and always remain humble, Blair said. He said that’s something he learned during his decade as prime minister. Blair was the longest-serving leader of Britain’s Labour Party.

Blair recalled meeting President Nelson Mandela during the height of the anti-apartheid movement in South Africa, saying the encounter taught him the importance of humility.

Blair described Mandela as a modest man despite his stature. He told graduates to aspire to this approach, adding, “the greatest people I’ve met in life are humble.”

Blair drew frequent laughs from the crowd by sharing the embarrassing moments that he says also helped remind him of this important lesson.

He recalled tripping over a carpet during the ceremony of kissing hands, where the incoming prime minister meets the queen at Buckingham Palace. Instead of gently brushing the queen’s ring, he “enveloped the queen’s hand,” Blair told the Colby crowd.

Blair may have benefited from the humorous tone set by the previous speaker, who warmed up the audience.

Samuel C. Deeran, the Colby Class of 2012 speaker, welcomed his fellow graduates to the “Comedy Central roast of Tony Blair.”

Deeran, of Falmouth, said it must have been a mistake that he was opening for a prime minister. And he joked that he wanted some of the same perks, saying he deserved a private jet, a fluffer-nutter sandwich and “a personal play date with George W. Bush.”

Deeran said he didn’t appreciate the value of a Colby education until he dropped out his junior year. He moved to Los Angeles to make it as a standup comic and quickly learned the harsh lessons of the real world.

Blair complimented Deeran, saying he would make a great politician with his ability to cut people down to size.