In emotional-at-times sit-down with MSNBC’s Rachel Maddow, VP says keeping promise to end the war in Iraq “makes everything worthwhile on this job for me.”

Biden: “I feel like…I did something that or participated in something being done that I can be proud of the rest of my life.”

Also defends admin.’s action in Libya — no loss of life — and says he “hope[s] we’ve learned the lesson that going it alone…should be the very last option.”