I do care if it was moral.
Labour's Lord Soley explained the dangers of getting obsessed with international law yesterday:
As I have pointed out here before, one of the most important interventions of all time was particularly important to this House—the 19th-century intervention by the British, using the Royal Navy, to stop the transatlantic slave trade. Captains of Royal Navy vessels were successfully sued in court cases in this House for arresting slave traders on the high seas and for entering the ports of other countries and burning the empty slave boats. All the usual complaints were around saying that we should not do it. Why? In the Times at that period you could read about the cause to bring our British sailors home because they were dying of tropical fevers and so on and it was felt that it was not a war for us. Slavery was normal. Trading slaves was normal. It became abnormal because we made it so, even though it was fully lawful at the time.
People have to be very careful in that if they get the balance of morality and law wrong, they could end up defending the indefensible for legal reasons. I have made this argument before. The lawyers today are very much in the position of lawyers in the 1950s and 1960s who argued that if a man beat his wife and kids in the street he could be arrested but if he did it in his own home he could not be touched. That is what we do in international affairs. The Treaty of Westphalia means that the nation state is still the dominant idea of the day. So if Saddam Hussein invades Kuwait, we will have him, but if he gases his own people we will let him get on with it."