(although we contributed nothing towards it!)

perhaps therefore:

in the light of others' victory

with no effort we always win

ie, in this case, the profits - the spoils of war - and not the activity of fighting itself. See:

"piece (of the action) and bit of the action; slice of the action
Sl. a share in the activity or the profits"

http://idioms.thefreedictionary.com/a slice of the action

:-)

The metaphor of "mojar nuestro pan" implies that they (the men) do the hard work and we get the benefit. In context, "reap the spoils" alone would probably imply this, but I would be inclined to add "of their victory" to make it clear. I basically agree with Denise's answer, with the addition of "their": enjoy the fruits of their victory. "Enjoy the fruits of victory" implies one's own victory, whereas for me "reap the spoils", a very similar expression, lends itself better to the idea of usurping the fruits of another person's victory, benefiting from someone else's efforts, which is what is involved here.

I think these examples illustrate the sense I am trying to capture here:

"pues nuestro deporte nacional es organizarnos en corporación para mojar nuestro pan en la salsera del Estado"
http://www.lagaceta.com.ar/nota/imprimir/36497/
This sounds a bit like "the gravy train"!

"The dire wolves watch with anticipation, hoping to reap the spoils of the sabertooth's meal."
http://www.amnh.org/exhibitions/permanent/fossilhalls/timeli...