He's talking about soldiers, but let us not forget the 38 WASP who made the ultimate sacrifice in WWII, the men and women of the ambulance corps and other services who have been killed in wars since the beginning of time, and of course the women (and men of course) who have died in Iraq and Afghanistan.
They died for honor and country.
The young dead soldiers do not speak.
Nevertheless, they are heard in the still houses:
who has not heard them?
They have a silence that speaks for them at night and when the clock counts.
They say: We were young. We have died.
They say: We have done what we could but until it is finished it is not done.
They say: We have given our lives but until it is finished no one can know what our lives gave.
They say: Our deaths are not ours: they are yours, they will mean what you make them.
They say: Whether our lives and our deaths were for
peace and a new hope or for nothing we cannot say,
it is you who must say this.
We leave you our deaths. Give them their meaning.
We were young, they say. We have died;
Archibald MacLeish, 1941