To ignore history is to be blind in one eye: to forget history is to be blind in both eyes. Were the Americans obliged to have given Christmas presents to Japan in December 1941? If you are being stabbed, at what time do you react? After being stabbed many times or just before the point of death? Pacifism is the evil of inaction. One mans terrorist is another mans 'freedom fighter': Dunblane, Hungerford, Columbine, Washington the sniper from the car, they were all terrorists. They were not 'Freedom Fighters'. Terrorism is going down to the shop and not knowing if you are to return alive. I go about my lawful business, so why can't they.
Some warmongering dictators have words to the effect 'We have many homeless, we are hungry', responding to their people by building up stocks of arms and expecting aid at the same time.