Is it the leaders of a country that makes them good, bad, at peace or in war? Or is it the led who are the majority that determines what becomes of a nation.
On short run, it's the leaders who make the country good or bad, considering they were put where they are to manage the country. However, if times go by and nothing good is done by the leaders, it's the responsability of the led to choose a new commander. In countries where we see a long lasting precarious economical and social situation for several decades, you can be assured the problem isn't exactly the leaders (at least, they aren't the cause of the problem, but a consequence).
The leaders are a reflex of the people in the mirror. They display the qualities of the people they govern. If the leader is corrupt and the country doesn't unite to remove him and put someone honest in his spot, you can be pretty certain the people of that country is corrupt as well. So, the led are the main problem. Democracy is a failure because of that, as it values quantity over quality.