It may be true that morals are subjective, but it is far from clear. The existence of different sets of morality among different cultures or species does not, in any way, mean that objective morality does not exist. Some cultures or species might just be wrong about their morality.
Ugh. Be careful, bluskool, where you go with this slippery slope.
"That country is wrong to claim that it is immoral for us to bomb them, they clearly don't understand how it is morally right."
If morals are objective, and one group can be 'right' about their morality, and another group 'wrong', how do you tell which is which? It becomes akin to an argument between two different Christian churches: God exists, but you are wrong about what he is, we are right.