People with great foresight who act on it to prevent disasters and save lives are far more likely to be criticised than praised.
This was pointed out by financial mathematician Nassim Nicholas Tabel in The Black Swan. He argues they would have no proof that a disaster was avoided: for all we know, they might have cried wolf. The only fact is that they wasted valuable resources on an imaginary threat.
I raise it here because an outraged reader sent me a note rounding on my column yesterday  that he said unfairly singled out the US response, or lack of response, to the Rwandan genocide that started 20 years ago this week. Politicians like Bill Clinton instinctively understand Tabel's point. I agree that partly explains his inaction on Rwanda.
He and his top advisers calculated, correctly at the time, that the risks of committing substantial US/UN troops needed in Rwanda were far higher than doing nothing. They would have faced certain public criticism and congressional backlash. Suppose they had committed troops and stopped a potential genocide. Clinton would not be praised but instead would have been rounded on for risking American lives in the name of faraway tribal violence. But that's too charitable; Clinton's sins went much further.
A full account of the cynical US response can be found in A Problem From Hell by Samantha Power, the current US ambassador to the UN. Suffice to say that far from not knowing or being confused, from the first days the CIA, the State Department and a marine special forces team sent deep inside Rwanda all reported killings on an extraordinary and systematic scale.
Washington made what may be called a classic "category error". They were thinking Burundi (tribal violence) and Somalia (botched US humanitarian-military operations) instead of the Holocaust.
Like old generals, they were thinking of "the last war", a fight between the Tutsi and Hutu in Burundi in October 1993 which killed more than 50,000. Despite the implicit racism, that was an acceptable level of violence in Rwanda for the Americans.
Why blame the US? Because it was at the apex of the international system and no viable UN/African operations could have got off the ground without US support.