What “contributions”?
Hagel nearly died in combat for his country. whether we like or dislike his politics, that’s a contribution to be honored.
His contributions are many. If you had been watching C-SPAN hearings on Hagel confirmation this morning, you would have been impressed with the comments of Illinois Senator Dick Durbin on the many ways Hagel has served the country. They were many, and for reasons of wanting to be totally accurate in response to your question, I will comment on one that really stands out. During the Viet Nam War he was sent to a safe post in Europe. At that time, he requested a change so he could participate in the war zone in Viet Nam. There, in the war zone, he received many awards for performance in active duty.