Surely this is the answer to all the world's problems. Twice a day, every world leader should be forced to take a long dip in a frozen lake or a specially chilled swimming pool where the water is freezing. Beating them with birch branches afterwards could be another option.
This would slow down sudden rushes of blood to the head, cool down overly-aggressive warmongers, retard the ardour of over-sexed Presidents, confront leaders daily with the simple reality of nature, and, in some cases, stimulate the blood flow in those who are almost moribund.
As well, the ten minutes of searing, aching pain each morning and evening would make each leader think carefully about whether being a leader was really worth it so only the most dedicated ones would endure it.
Cool heads would finally prevail, I'm sure of it!