world Strongest leader?

[Naida_BR]

Definitely Nigerian president ....age 86 and still gunning for more Years in the office while battling with serious health problems

This doesn't make him power.
Little to no people are aware of who is exactly the Nigerian president. He might be only powerful or corrupted so as to be president for so many years.
The powerful presidency comes from the fact that he controls the international events.

[aiguy]

I think in this option one person should be more added who is the supreme leader of Iran. he is not only an Irani leader but also a great leader of Shia Muslim all over the world.