Putin and Erdogan are building a friendship. This includes enjoying a ceremony to open a massive mosque in Moscow, or increasing economic ties.
Erdogan is a strong proponent of Islam. He publicly read a poem including this line, "The mosques are our barracks the domes our helmets, the minarets our bayonets and the faithful our soldiers."
Among his policies to spread Islam are included, the push to remove a ban on Islamic headscarfts in public institutions, build a huge amount of mosques. Dissent is not allowed.