In 2029 Trump will be out. Putin, if still alive, will have lost a major ally.

Why then do they all invariably give such a definite date rather than something like "next five years" or "next decade" or even other dates like "2028/2030/2031/2032"? Somewhere a decision has been made about this date. (Historically, we know that World War One, for instance, was actively planned and prepared for for a number of years before it happened.)