Former U. N. Secretary-General Kofi Annan exhorted University at Buffalo students Wednesday night to “think globally.”

“You cannot afford to think locally, given the world we live in,” Annan said. “Your decisions can have an impact, good or bad, on people across the planet.”

Annan, who headed the United Nations from 1997 to 2006 and earned a Nobel Peace Prize, opened the 2009-10 Distinguished Speakers Series at UB’s Alumni Arena.

The Ghanian-born Annan, 71, shared with the students five principles that he said are essential for the future of international relations, likening them to lessons he learned as secretary- general.

What those principles encompass, Annan said, is collective responsibility. “We are all responsible for each other’s security,” he said.

They also include ensuring that everyone has the chance to benefit from global prosperity, and he noted that both security and prosperity depend on an adherence to the principles of human rights and the rule of law.

“No state can make its own actions legitimate in the eyes of others,” he said. “When power, especially military force, is used, the world will consider it legitimate only when convinced that it is being used for the right purpose.”

He added that nations also must be accountable to one another, as well as to a broad range of what he called non-state actors. Their role, he said, is to provide a sort of conscience for governments to ensure that they adhere to international or universal codes of conduct.

“The U. S. has given the world an example of a democracy in which everyone, including the most powerful, is subject to legal restraint,” he said. As such, he added, America is afforded a unique “opportunity to entrench the same principles at the global level.”

Annan’s fifth principle is what he called multilateralism, which he said is best achieved through the United Nations that was handed down to us by President Harry Truman and his contemporaries. Annan said he continues to advocate Security Council reform.

“The U. N. Security Council still reflects the geopolitical realities of 1945 and not today’s world,” he said.

Annan and the United Nations received the Nobel Peace Prize in 2001.

Wednesday, he recalled that it was 50 years ago when he first traveled from Africa to attend Macalester College in Minnesota. Annan said he was unprepared for the cold and at first refused to wear earmuffs— because they looked undignified— until he experienced firsthand the frigid Minnesota winters.

“Eventually, I bought the biggest pair I could find,” Annan said. “It was a lesson for me that you don’t walk into an environment and pretend to know better than the natives.”