http://revach.net/article.php?id=4701

Section: Parshas HaShavua   Category: Quick Vort
Parshas Shoftim: Netziv - A King Is Not For Every Society
"Ki Savo El HaAretz... V'Amarta Asima Alai Melech; When you come into Eretz Yisrael... and you will say place upon us a king."  The Mitzva of making a king is one of the Taryag Mitzvos.  Why does the Torah say, "V'AMarta; When you will say that you want a king,"  Is it optional?

The Netziv answers that each country and each society is different.  "Some countries cannot function without a strong leader, while other cultures cannot tolerate a king dictating the country's order and policies.  The leadership of a country needs to match the society, and having a type of leadership that is incompatible with the people, can have consequences bordering on Sakanas Nefashos," says the Netziv.  "Such drastic matters cannot be forced upon them by a Mitzvas Aseh.
Therefore, the Mitzva of coronating a King is a democratic decision.  Only when the people are ready for it and ask for it, only then must the Sanhedrin anoint a king.  This is seen in history as Bnei Yisrael did not have a king until after being in Eretz Yisrael for 300 years.  Until then there was no consensus for it," says the Netziv.