The Caliphate is not allowed to force any non-Muslim to abandon his/her belief. Rather the non-Muslims should accept Islam after being intellectually convinced of the Islamic belief.
The Ahdnama is an agreement written by Sultan Muhammed al-Fatih who is famous for conquering Constantinople and fulfilling the prophecy of the Prophet Muhammed ﷺ that Muslims would one day conquer the city.
A K Newell, writes from Bosnia-Herzegovina After touching down in Sarajevo and a brief stop at passport control we made our way outside the airport to catch a taxi. Up until this point, the flight, the airport, the baggage collection, everything was perfectly normal as you’d expect from any European capital. We flagged down a taxi, managing to haggle a fairly reasonable price despite the soaring petrol prices, and proceeded to our destination. The taxi ride from the airport is where you begin to notice that this is no ordinary European city. The NATO army truck driving past and rows of derelict houses punctured by machine gun holes give indications that this now calm city was once the scene of a terrible war. Our taxi driver speaks of war criminals, The Hague and his time fighting with the army, but this is not the Second World War. This is a war that ended just thirteen years ago in the heart of Europe.