Can democracy ensure a peaceful Pakistan?

You are talking about politics. Anything can be true if you keep saying it, and nothing is true if you can't be forced to admit it. "Democracy" means people rule, and that means mob rule. People like to rule, but they don't like to be ruled, but they will put up with it if everybody is ruled equally, and then they want exceptions for themselves. This is stupid, so the society eventually collapses. Always. After the collapse they rebuild and start a government that is slightly different but just as bad. Always. Democracy can not ensure anything if the people are bonkers. Neither can any other form of government.