Going to war.

That is far too broad. Some men would feel elated and some would fight every step of the way. Make up whatever seems appropriate to your character, because it is, after all your character.

Time period/place matters as well. Think WWII in the Soviet Union, with the German invasion in progress; as opposed to the back end of the Vietnam War and the response of your average American hippie. The cultural zeitgeist couldn't be more different. And as Drachen pointed out, there are dramatic individual differences, even in a particular group.

If you give us some idea of time period, setting, etc., we might be able to point you to some related cultural attitudes towards war.

Consider even the differences between the British at the start of WWI, where men were joining up in high spirits, and later in the war, when conscription was introduced and stories of the conditions had begun creeping back.