Can leadership be taught or learned?

I think it can. If someone has a will and desire to be a leader, there are numerous opportunities for education and acquiring needed skills: seminars, conferences, universities where business can be taught, workshops... Skills that leader needs are often from various fields: public relations, media, oratory, laws, communication, languages...

On some other question I've answered that leaders can't lead without charisma. It can also be learned. Of course, it is a plus if leader has unique talent and natural charisma. In that case, his/her talent can only be progressed thanks to the abovementioned education.