What lessons did Mehmat learn from his mistakes?

He learned that it is necessary to make preparations before taking any government decision, it is necessary to be strategic, especially in military campaigns.

Explanation:

Mehmat had already caused a strong decline in the Ottoman empire, due to unprepared and poorly planned missions. However, he learned from his mistakes and took a different stand when he ascended the throne again. Mehmat, learned to make strategies, to think before making decisions, to establish a plan and to delimit all the steps, mainly in military campaigns.

bismarck believed in using force

is the correct answer!