At some point, a US president may need to send soldiers into a situation in which they will very likely die, in order to win a war. It has happened before, and it may happen again. If the president allows visits to wounded veterans to weaken his resolve, the consequences could be very bad. That's what Eliot Cohen is alluding to. He is not suggesting that the president should not care -- he is suggesting that the president needs to do what is necessary to win a war if one happens.
> Be smart, war is a racket, and suggesting a president should not be worried about the lives of the people he harms is fucked up.
Nobody suggested that the president should not worry about the lives of soldiers. Your interpretation is unreasonably uncharitable and is in fact a straw man.