Big and tall soldiers are more likely to survive battle: a possible explanation for the 'returning soldier effect' on the secondary sex ratio

It is widely known that more boys are born during and immediately after wars, but there has not been any ultimate (evolutionary) explanation for this 'returning soldier effect'. Here, I suggest that the higher sex ratios during and immediately after wars might be a byproduct of the fact that taller soldiers are more likely to survive battle and that taller parents are more likely to have sons.