One does not know "when" an avalanche will occur, but one can identify the conditions making it more probable.
Well, I know that my death is inevitable, not just probable. But, I am certainly not going to schedule my funeral before it's time.
I am optimistic about our country's future. I can't tell you which country will be dominant in 200 years, but I can tell you that we're starting this race with a big head start. There isn't any place I'd rather be right now.