Soldiers

Why there are soldiers?

Ouyang Lin looked at the instructor in front of her and furrowed her delicate eyebrows. 

"Soldiers are there to protect their homeland, to fight against invaders who dared to step onto our lands," Ouyang Lin replied.

The instructor nodded.

There was no definite answer for this question but most of the people would have similar answers. 

"In that case, do you know why there are a lot of soldiers?"

"Because it can do more things?" Ouyang Lin asked back.

The instructor shook his head and then replied, "It's not entirely true. The most basic answer is because there is strength in number."

There are strength in number.

It was something that many people knew but might not actually truly understand how it affect their lives. Most people would follow what public opinion required them to do and 

behaved in the way that can be accepted by the normal people.

Why?