With a smattering of self-deprecating jokes and a few references to a harrowing confirmation process, new Secretary of Defense Chuck Hagel described what he sees as a “historic” moment for the U.S. in a changing world.

Vice President Joe Biden administered Hagel’s ceremonial swearing-in  this afternoon, where Hagel told gathered Pentagon and diplomatic officials it will take wise leadership and a team effort to confront what he called an unprecedented time of change.

“It’s going to take a team effort in this country today to help self-correct where we are, and where we have come from, and what this country has been through, as we come out of a second war, new threats, new challenges– I think this is probably an unprecendent time of change,” he said.

Hagel said he thinks we are in a “smilar time in the world” as the so-called greatest generation, still the the greatest force in the world for good but facing different kinds of threats, including cyber security and an unsteady global scene.

The new Secretary of Defense also emphasized the need for teamwork at a time when a strong leadership, always important, is “critical.”

“It is not anything about me,” he said. “I am just lucky enough to be a passing steward at this great moment. Not many people ever have the opportunity to shape and define the world, and shape and define the future, and shape and define a very unsteady world,” he added. “And we all have that opportunity now, and it’s historical.”

Hagel concluded on an optimistic note.

“Together we will make this a better world and we’ll make a better world for all mankind,” he said.