Here are the requirements needed in a leader... according to allah swt.
[Yusufali 2:247] Their Prophet said to them: "Allah hath appointed Talut as king over you." They said: "How can he exercise authority over us when we are better fitted than he to exercise authority, and he is not even gifted, with wealth in abundance?" He said: "Allah hath Chosen him above you, and hath gifted him abundantly with knowledge and bodily prowess: Allah Granteth His authority to whom He pleaseth. Allah careth for all, and He knoweth all things."
Commentary:
(In continuation of verse 246).
Samuel said to the Jews that Allah had raised Talut (Saul) to be a king over them. According to 1 Samuel 10: 23 he was a head taller than anyone else. There was no one like him in the nation of Jews. He was called Talut on account of his height and strength. The people despised Talut's kingship because he did not have wealth, which they had in abundance.
The essential qualities required in a leader are clearly discernible if careful attention is paid to the reply given by Samuel:
Inallahas-tafahu alaykum-Allah has chosen him in preference to you. According to the divine law a
leader of the people (temporal or spiritual) is chosen by Allah, not by the people.
Wa zadahu bastatan fil ilmi wal jism-And He has increased him abundantly in knowledge and physique. The chosen leader is given knowledge and physical strength by Allah Himself. The true leader possesses divinely endowed knowledge and strength to guide and protect the people whom Allah loves and cherishes.
Wallahu yuti mulkuhu man yasha - Allah grants His kingdom to whomever He pleases. The sovereignty and the kingdom of the universe belong to Allah, therefore, on His behalf, the authority to lead and guide the created beings, is with him whom Allah chooses. He chooses whomever He likes, whether the people like it or not.
Wallahu wasi-un alim-Verily Allah is vast (giver of ample bounties), all-knowing. The bounties the people receive and use for the satisfaction of their needs and wants are given to them by Allah.
No human being can claim credit for providing them to the people. What is good and what is bad for the people is known only to Allah. This knowledge is given to those leaders whom He Himself elects to lead and guide the people.
Now you can apply these characteristics, for choosing a leader in this day and age, and you can also look back in history and see if the right choices had been made to elect a leader - a leader who had the most knowlege and was the bravest of all.